diff --git a/broker/src/main/java/io/moquette/imhandler/AddGroupMember.java b/broker/src/main/java/io/moquette/imhandler/AddGroupMember.java
index 650425241..51c808841 100644
--- a/broker/src/main/java/io/moquette/imhandler/AddGroupMember.java
+++ b/broker/src/main/java/io/moquette/imhandler/AddGroupMember.java
@@ -43,7 +43,7 @@ public ErrorCode action(ByteBuf ackPayload, String clientID, String fromUser, Pr
             if (request.hasNotifyContent() && request.getNotifyContent().getType() > 0) {
                 sendGroupNotification(fromUser, request.getGroupId(), request.getToLineList(), request.getNotifyContent());
             } else {
-                WFCMessage.MessageContent content = new GroupNotificationBinaryContent(request.getGroupId(), fromUser, null, getMemberIdList(request.getAddedMemberList())).getAddGroupNotifyContent();
+                WFCMessage.MessageContent content = new GroupNotificationBinaryContent(request.getGroupId(), fromUser, null, getMemberIdList(request.getAddedMemberList())).setExtra(request.getExtra()).getAddGroupNotifyContent();
                 sendGroupNotification(fromUser, request.getGroupId(), request.getToLineList(), content);
             }
         }
diff --git a/broker/src/main/java/io/moquette/imhandler/CreateGroupHandler.java b/broker/src/main/java/io/moquette/imhandler/CreateGroupHandler.java
index a4e5ecf8d..5d98e639b 100644
--- a/broker/src/main/java/io/moquette/imhandler/CreateGroupHandler.java
+++ b/broker/src/main/java/io/moquette/imhandler/CreateGroupHandler.java
@@ -63,7 +63,7 @@ public ErrorCode action(ByteBuf ackPayload, String clientID, String fromUser, Pr
             if(request.hasNotifyContent() && request.getNotifyContent().getType() > 0) {
                 sendGroupNotification(fromUser, groupInfo.getTargetId(), request.getToLineList(), request.getNotifyContent());
             } else {
-                WFCMessage.MessageContent content = new GroupNotificationBinaryContent(groupInfo.getTargetId(), fromUser, groupInfo.getName(), "").getCreateGroupNotifyContent();
+                WFCMessage.MessageContent content = new GroupNotificationBinaryContent(groupInfo.getTargetId(), fromUser, groupInfo.getName(), "").setExtra(request.getMemberExtra()).getCreateGroupNotifyContent();
                 sendGroupNotification(fromUser, groupInfo.getTargetId(), request.getToLineList(), content);
             }
         }
diff --git a/common/src/main/java/cn/wildfirechat/pojos/GroupNotificationBinaryContent.java b/common/src/main/java/cn/wildfirechat/pojos/GroupNotificationBinaryContent.java
index a5e7e6fc5..7d9d1f9bb 100644
--- a/common/src/main/java/cn/wildfirechat/pojos/GroupNotificationBinaryContent.java
+++ b/common/src/main/java/cn/wildfirechat/pojos/GroupNotificationBinaryContent.java
@@ -13,6 +13,7 @@
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.protobuf.ByteString;
+import io.netty.util.internal.StringUtil;
 
 import java.util.List;
 
@@ -32,6 +33,8 @@ public class GroupNotificationBinaryContent {
     //value2(member or something)
     private String m;
 
+    private String extra;
+
     public GroupNotificationBinaryContent() {
     }
 
@@ -89,8 +92,18 @@ public void setMs(List<String> ms) {
         this.ms = ms;
     }
 
+    public GroupNotificationBinaryContent setExtra(String extra) {
+        this.extra = extra;
+        return this;
+    }
+
     public WFCMessage.MessageContent getGroupNotifyContent(int groupContentType) {
-        return WFCMessage.MessageContent.newBuilder().setType(groupContentType).setData(ByteString.copyFromUtf8(new GsonBuilder().disableHtmlEscaping().create().toJson(this))).build();
+        WFCMessage.MessageContent.Builder builder = WFCMessage.MessageContent.newBuilder().setType(groupContentType).setData(ByteString.copyFromUtf8(new GsonBuilder().disableHtmlEscaping().create().toJson(this)));
+        if(!StringUtil.isNullOrEmpty(extra)) {
+            builder.setExtra(extra);
+        }
+        return builder.build();
+
     }
 
     public WFCMessage.MessageContent getAddGroupNotifyContent() {
diff --git a/common/src/main/java/cn/wildfirechat/pojos/InputAddGroupMember.java b/common/src/main/java/cn/wildfirechat/pojos/InputAddGroupMember.java
index 4b39f262a..92202ef01 100755
--- a/common/src/main/java/cn/wildfirechat/pojos/InputAddGroupMember.java
+++ b/common/src/main/java/cn/wildfirechat/pojos/InputAddGroupMember.java
@@ -17,6 +17,7 @@
 public class InputAddGroupMember extends InputGroupBase {
     private String group_id;
     private List<PojoGroupMember> members;
+    private String member_extra;
 
     public String getGroup_id() {
         return group_id;
@@ -34,6 +35,14 @@ public void setMembers(List<PojoGroupMember> members) {
         this.members = members;
     }
 
+    public String getMember_extra() {
+        return member_extra;
+    }
+
+    public void setMemberExtra(String extra) {
+        this.member_extra = extra;
+    }
+
     public boolean isValide() {
         return true;
     }
@@ -41,6 +50,9 @@ public boolean isValide() {
     public WFCMessage.AddGroupMemberRequest toProtoGroupRequest() {
         WFCMessage.AddGroupMemberRequest.Builder addGroupBuilder = WFCMessage.AddGroupMemberRequest.newBuilder();
         addGroupBuilder.setGroupId(group_id);
+        if(!StringUtil.isNullOrEmpty(member_extra)) {
+            addGroupBuilder.setExtra(member_extra);
+        }
         for (PojoGroupMember pojoGroupMember : getMembers()) {
             WFCMessage.GroupMember.Builder groupMemberBuilder = WFCMessage.GroupMember.newBuilder().setMemberId(pojoGroupMember.getMember_id());
             if (!StringUtil.isNullOrEmpty(pojoGroupMember.getAlias())) {
diff --git a/common/src/main/java/cn/wildfirechat/pojos/InputCreateGroup.java b/common/src/main/java/cn/wildfirechat/pojos/InputCreateGroup.java
index 4c6697489..39cae453a 100755
--- a/common/src/main/java/cn/wildfirechat/pojos/InputCreateGroup.java
+++ b/common/src/main/java/cn/wildfirechat/pojos/InputCreateGroup.java
@@ -16,6 +16,7 @@
 
 public class InputCreateGroup extends InputGroupBase {
     private PojoGroup group;
+    private String member_extra;
 
     public boolean isValide() {
         return true;
@@ -87,6 +88,9 @@ public WFCMessage.CreateGroupRequest toProtoGroupRequest() {
 
         WFCMessage.CreateGroupRequest.Builder createGroupReqBuilder = WFCMessage.CreateGroupRequest.newBuilder();
         createGroupReqBuilder.setGroup(groupBuilder);
+        if(!StringUtil.isNullOrEmpty(member_extra)) {
+            createGroupReqBuilder.setMemberExtra(member_extra);
+        }
         if (to_lines != null) {
             for (Integer line : to_lines
             ) {
@@ -107,4 +111,12 @@ public PojoGroup getGroup() {
     public void setGroup(PojoGroup group) {
         this.group = group;
     }
+
+    public String getMember_extra() {
+        return member_extra;
+    }
+
+    public void setMember_extra(String member_extra) {
+        this.member_extra = member_extra;
+    }
 }
diff --git a/sdk/src/main/java/cn/wildfirechat/sdk/GroupAdmin.java b/sdk/src/main/java/cn/wildfirechat/sdk/GroupAdmin.java
index 35d1205b9..decb8a4de 100644
--- a/sdk/src/main/java/cn/wildfirechat/sdk/GroupAdmin.java
+++ b/sdk/src/main/java/cn/wildfirechat/sdk/GroupAdmin.java
@@ -2,14 +2,13 @@
 
 import cn.wildfirechat.common.APIPath;
 import cn.wildfirechat.pojos.*;
-import cn.wildfirechat.proto.ProtoConstants;
 import cn.wildfirechat.sdk.model.IMResult;
 import cn.wildfirechat.sdk.utilities.AdminHttpUtils;
 
 import java.util.List;
 
 public class GroupAdmin {
-    public static IMResult<OutputCreateGroupResult> createGroup(String operator, PojoGroupInfo group_info, List<PojoGroupMember> members, List<Integer> to_lines, MessagePayload  notify_message) throws Exception {
+    public static IMResult<OutputCreateGroupResult> createGroup(String operator, PojoGroupInfo group_info, List<PojoGroupMember> members, String member_extra, List<Integer> to_lines, MessagePayload  notify_message) throws Exception {
         String path = APIPath.Create_Group;
         PojoGroup pojoGroup = new PojoGroup();
         pojoGroup.setGroup_info(group_info);
@@ -17,6 +16,7 @@ public static IMResult<OutputCreateGroupResult> createGroup(String operator, Poj
         InputCreateGroup createGroup = new InputCreateGroup();
         createGroup.setGroup(pojoGroup);
         createGroup.setOperator(operator);
+        createGroup.setMember_extra(member_extra);
         createGroup.setTo_lines(to_lines);
         createGroup.setNotify_message(notify_message);
 
@@ -85,12 +85,13 @@ public static IMResult<PojoGroupMember> getGroupMember(String groupId, String me
         return AdminHttpUtils.httpJsonPost(path, input, PojoGroupMember.class);
     }
 
-    public static IMResult<Void> addGroupMembers(String operator, String groupId, List<PojoGroupMember> groupMembers, List<Integer> to_lines, MessagePayload  notify_message) throws Exception {
+    public static IMResult<Void> addGroupMembers(String operator, String groupId, List<PojoGroupMember> groupMembers, String member_extra, List<Integer> to_lines, MessagePayload  notify_message) throws Exception {
         String path = APIPath.Group_Member_Add;
         InputAddGroupMember addGroupMember = new InputAddGroupMember();
         addGroupMember.setGroup_id(groupId);
         addGroupMember.setMembers(groupMembers);
         addGroupMember.setOperator(operator);
+        addGroupMember.setMemberExtra(member_extra);
         addGroupMember.setTo_lines(to_lines);
         addGroupMember.setNotify_message(notify_message);
         return AdminHttpUtils.httpJsonPost(path, addGroupMember, Void.class);
diff --git a/sdk/src/main/java/cn/wildfirechat/sdk/Main.java b/sdk/src/main/java/cn/wildfirechat/sdk/Main.java
index 743de5b11..a0f7778c7 100644
--- a/sdk/src/main/java/cn/wildfirechat/sdk/Main.java
+++ b/sdk/src/main/java/cn/wildfirechat/sdk/Main.java
@@ -503,7 +503,7 @@ static void testGroup() throws Exception {
         member3.setMember_id("user3");
         members.add(member3);
 
-        IMResult<OutputCreateGroupResult> resultCreateGroup = GroupAdmin.createGroup(groupInfo.getOwner(), groupInfo, members, null, null);
+        IMResult<OutputCreateGroupResult> resultCreateGroup = GroupAdmin.createGroup(groupInfo.getOwner(), groupInfo, members, null, null, null);
         if (resultCreateGroup != null && resultCreateGroup.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS) {
             System.out.println("create group success");
         } else {
@@ -575,7 +575,7 @@ static void testGroup() throws Exception {
         m.setMember_id("user1");
         m.setAlias("hello user1");
 
-        voidIMResult = GroupAdmin.addGroupMembers("user1", groupInfo.getTarget_id(), Arrays.asList(m), null, null);
+        voidIMResult = GroupAdmin.addGroupMembers("user1", groupInfo.getTarget_id(), Arrays.asList(m), null, null, null);
         if (voidIMResult != null && voidIMResult.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS) {
             System.out.println("add group member success");
         } else {
@@ -1065,7 +1065,43 @@ static void testChannelApi() throws Exception {
             System.exit(-1);
         }
 
-        IMResult<Void> voidIMResult = ChannelAdmin.destroyChannel(inputCreateChannel.getTargetId());
+        String subscriber = "aaa";
+        IMResult<Void> voidIMResult = ChannelAdmin.subscribeChannel(inputCreateChannel.getTargetId(), subscriber);
+        if(voidIMResult != null && voidIMResult.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS) {
+            System.out.println("subscribeChannel success");
+        } else {
+            System.out.println("subscriber channel failure");
+            System.exit(-1);
+        }
+
+        Thread.sleep(100);
+        IMResult<OutputBooleanValue> booleanIMResult = ChannelAdmin.isUserSubscribedChannel(subscriber, inputCreateChannel.getTargetId());
+        if(booleanIMResult != null && booleanIMResult.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS && booleanIMResult.getResult().value) {
+            System.out.println("subscribe status is correct");
+        } else {
+            System.out.println("subscribe status is incorrect");
+            System.exit(-1);
+        }
+
+
+        voidIMResult = ChannelAdmin.unsubscribeChannel(inputCreateChannel.getTargetId(), subscriber);
+        if(voidIMResult != null && voidIMResult.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS) {
+            System.out.println("unsubscribeChannel success");
+        } else {
+            System.out.println("unsubscriber channel failure");
+            System.exit(-1);
+        }
+        Thread.sleep(100);
+
+        booleanIMResult = ChannelAdmin.isUserSubscribedChannel(subscriber, inputCreateChannel.getTargetId());
+        if(booleanIMResult != null && booleanIMResult.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS && !booleanIMResult.getResult().value) {
+            System.out.println("subscribe status is correct");
+        } else {
+            System.out.println("subscribe status is incorrect");
+            System.exit(-1);
+        }
+
+        voidIMResult = ChannelAdmin.destroyChannel(inputCreateChannel.getTargetId());
         if(voidIMResult != null && voidIMResult.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS) {
             System.out.println("success");
         } else {
@@ -1442,7 +1478,7 @@ static void testRobot() throws Exception {
         member3.setMember_id("user3");
         members.add(member3);
 
-        IMResult<OutputCreateGroupResult> resultCreateGroup = robotService.createGroup(groupInfo, members, null, null);
+        IMResult<OutputCreateGroupResult> resultCreateGroup = robotService.createGroup(groupInfo, members, null, null, null);
         if (resultCreateGroup != null && resultCreateGroup.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS) {
             System.out.println("create group success");
         } else {
@@ -1486,7 +1522,7 @@ static void testRobot() throws Exception {
         m.setMember_id("user0");
         m.setAlias("hello user0");
 
-        voidIMResult = robotService.addGroupMembers(groupInfo.getTarget_id(), Arrays.asList(m), null, null);
+        voidIMResult = robotService.addGroupMembers(groupInfo.getTarget_id(), Arrays.asList(m), null, null, null);
         if (voidIMResult != null && voidIMResult.getErrorCode() == ErrorCode.ERROR_CODE_SUCCESS) {
             System.out.println("add group member success");
         } else {
diff --git a/sdk/src/main/java/cn/wildfirechat/sdk/RobotService.java b/sdk/src/main/java/cn/wildfirechat/sdk/RobotService.java
index ad8898e05..1fccc0745 100644
--- a/sdk/src/main/java/cn/wildfirechat/sdk/RobotService.java
+++ b/sdk/src/main/java/cn/wildfirechat/sdk/RobotService.java
@@ -96,13 +96,14 @@ public IMResult<Void> updateProfile(int/*MyInfoType*/ type, String value) throws
         return robotHttpUtils.httpJsonPost(path, pojo, Void.class);
     }
 
-    public IMResult<OutputCreateGroupResult> createGroup(PojoGroupInfo group_info, List<PojoGroupMember> members, List<Integer> to_lines, MessagePayload  notify_message) throws Exception {
+    public IMResult<OutputCreateGroupResult> createGroup(PojoGroupInfo group_info, List<PojoGroupMember> members, String member_extra, List<Integer> to_lines, MessagePayload  notify_message) throws Exception {
         String path = APIPath.Robot_Create_Group;
         PojoGroup pojoGroup = new PojoGroup();
         pojoGroup.setGroup_info(group_info);
         pojoGroup.setMembers(members);
         InputCreateGroup createGroup = new InputCreateGroup();
         createGroup.setGroup(pojoGroup);
+        createGroup.setMember_extra(member_extra);
         createGroup.setTo_lines(to_lines);
         createGroup.setNotify_message(notify_message);
 
@@ -163,11 +164,12 @@ public IMResult<PojoGroupMember> getGroupMember(String groupId, String memberId)
         return robotHttpUtils.httpJsonPost(path, input, PojoGroupMember.class);
     }
 
-    public IMResult<Void> addGroupMembers(String groupId, List<PojoGroupMember> groupMembers, List<Integer> to_lines, MessagePayload  notify_message) throws Exception {
+    public IMResult<Void> addGroupMembers(String groupId, List<PojoGroupMember> groupMembers, String member_extra, List<Integer> to_lines, MessagePayload  notify_message) throws Exception {
         String path = APIPath.Robot_Group_Member_Add;
         InputAddGroupMember addGroupMember = new InputAddGroupMember();
         addGroupMember.setGroup_id(groupId);
         addGroupMember.setMembers(groupMembers);
+        addGroupMember.setMemberExtra(member_extra);
         addGroupMember.setTo_lines(to_lines);
         addGroupMember.setNotify_message(notify_message);
         return robotHttpUtils.httpJsonPost(path, addGroupMember, Void.class);