diff --git a/example/bundle_test.go b/example/bundle_test.go
index a222b59..74fa113 100644
--- a/example/bundle_test.go
+++ b/example/bundle_test.go
@@ -1,6 +1,7 @@
 package example
 
 import (
+	"context"
 	"github.com/everFinance/everpay-go/sdk"
 	"github.com/everFinance/goar"
 	"github.com/everFinance/goar/types"
@@ -70,7 +71,8 @@ func TestBundleToArweave(t *testing.T) {
 
 	// send to arweave
 	wal, err := goar.NewWalletFromPath("jwkKey.json", "https://arweave.net")
-	tx, err := wal.SendBundleTx(bundle.BundleBinary, []types.Tag{
+	assert.NoError(t, err)
+	tx, err := wal.SendBundleTx(context.TODO(), 0, bundle.BundleBinary, []types.Tag{
 		{Name: "App", Value: "goar"},
 	})
 	assert.NoError(t, err)
diff --git a/go.mod b/go.mod
index c06756f..8600534 100644
--- a/go.mod
+++ b/go.mod
@@ -29,6 +29,7 @@ require (
 	github.com/mattn/go-isatty v0.0.14 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.1 // indirect
+	github.com/panjf2000/ants/v2 v2.6.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	golang.org/x/crypto v0.3.0 // indirect
 	golang.org/x/sys v0.2.0 // indirect
diff --git a/types/const.go b/types/const.go
index 91c7078..886bb1e 100644
--- a/types/const.go
+++ b/types/const.go
@@ -11,6 +11,9 @@ const (
 	NOTE_SIZE      = 32
 	HASH_SIZE      = 32
 
+	// concurrent submit chunks min size
+	DEFAULT_CHUNK_CONCURRENT_NUM = 50 // default concurrent number
+
 	// number of bits in a big.Word
 	WordBits = 32 << (uint64(^big.Word(0)) >> 63)
 	// number of bytes in a big.Word
diff --git a/uploader.go b/uploader.go
index 6d96d1d..a6bba66 100644
--- a/uploader.go
+++ b/uploader.go
@@ -1,11 +1,14 @@
 package goar
 
 import (
+	"context"
 	"errors"
 	"fmt"
+	"github.com/panjf2000/ants/v2"
 	"math"
 	"math/rand"
 	"strconv"
+	"sync"
 	"time"
 
 	"github.com/everFinance/goar/types"
@@ -148,6 +151,80 @@ func (tt *TransactionUploader) PctComplete() float64 {
 	return math.Trunc(fval * 100)
 }
 
+func (tt *TransactionUploader) ConcurrentOnce(ctx context.Context, concurrentNum int) error {
+	// post tx info
+	if err := tt.postTransaction(); err != nil {
+		return err
+	}
+
+	if tt.IsComplete() {
+		return nil
+	}
+
+	var wg sync.WaitGroup
+	if concurrentNum <= 0 {
+		concurrentNum = types.DEFAULT_CHUNK_CONCURRENT_NUM
+	}
+	p, _ := ants.NewPoolWithFunc(concurrentNum, func(i interface{}) {
+		defer wg.Done()
+		// process submit chunk
+		idx := i.(int)
+
+		select {
+		case <-ctx.Done():
+			log.Warn("ctx.done", "chunkIdx", idx)
+			return
+		default:
+		}
+		chunk, err := utils.GetChunk(*tt.Transaction, idx, tt.Data)
+		if err != nil {
+			log.Error("GetChunk error", "err", err, "idx", idx)
+			return
+		}
+		body, statusCode, err := tt.Client.SubmitChunks(chunk) // always body is errMsg
+		if statusCode == 200 {
+			return
+		}
+
+		log.Error("concurrent submitChunk failed", "chunkIdx", idx, "statusCode", statusCode, "gatewayErr", body, "httpErr", err)
+		// try again
+		retryCount := 0
+		for {
+			select {
+			case <-ctx.Done():
+				log.Warn("ctx.done", "chunkIdx", idx)
+				return
+			default:
+			}
+
+			retryCount++
+			if statusCode == 429 {
+				time.Sleep(1 * time.Second)
+			} else {
+				time.Sleep(200 * time.Millisecond)
+			}
+
+			body, statusCode, err = tt.Client.SubmitChunks(chunk)
+			if statusCode == 200 {
+				return
+			}
+			log.Warn("retry submitChunk failed", "retryCount", retryCount, "chunkIdx", idx, "statusCode", statusCode, "gatewayErr", body, "httpErr", err)
+		}
+	})
+
+	defer p.Release()
+	for i := 0; i < len(tt.Transaction.Chunks.Chunks); i++ {
+		wg.Add(1)
+		if err := p.Invoke(i); err != nil {
+			log.Error("p.Invoke(i)", "err", err, "i", i)
+			return err
+		}
+	}
+
+	wg.Wait()
+	return nil
+}
+
 /**
  * Uploads the next part of the Transaction.
  * On the first call this posts the Transaction
diff --git a/wallet.go b/wallet.go
index ac23d51..67f1ab6 100644
--- a/wallet.go
+++ b/wallet.go
@@ -1,6 +1,7 @@
 package goar
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"io/ioutil"
@@ -101,19 +102,28 @@ func (w *Wallet) SendDataSpeedUp(data []byte, tags []types.Tag, speedFactor int6
 	return w.SendTransaction(tx)
 }
 
-// SendTransaction: if send success, should return pending
-func (w *Wallet) SendTransaction(tx *types.Transaction) (types.Transaction, error) {
-	anchor, err := w.Client.GetTransactionAnchor()
+func (w *Wallet) SendDataConcurrentSpeedUp(ctx context.Context, concurrentNum int, data []byte, tags []types.Tag, speedFactor int64) (types.Transaction, error) {
+	reward, err := w.Client.GetTransactionPrice(data, nil)
 	if err != nil {
 		return types.Transaction{}, err
 	}
-	tx.LastTx = anchor
-	tx.Owner = w.Owner()
-	if err = w.Signer.SignTx(tx); err != nil {
-		return types.Transaction{}, err
+
+	tx := &types.Transaction{
+		Format:   2,
+		Target:   "",
+		Quantity: "0",
+		Tags:     utils.TagsEncode(tags),
+		Data:     utils.Base64Encode(data),
+		DataSize: fmt.Sprintf("%d", len(data)),
+		Reward:   fmt.Sprintf("%d", reward*(100+speedFactor)/100),
 	}
 
-	uploader, err := CreateUploader(w.Client, tx, nil)
+	return w.SendTransactionConcurrent(ctx, concurrentNum, tx)
+}
+
+// SendTransaction: if send success, should return pending
+func (w *Wallet) SendTransaction(tx *types.Transaction) (types.Transaction, error) {
+	uploader, err := w.getUploader(tx)
 	if err != nil {
 		return types.Transaction{}, err
 	}
@@ -121,6 +131,28 @@ func (w *Wallet) SendTransaction(tx *types.Transaction) (types.Transaction, erro
 	return *tx, err
 }
 
+func (w *Wallet) SendTransactionConcurrent(ctx context.Context, concurrentNum int, tx *types.Transaction) (types.Transaction, error) {
+	uploader, err := w.getUploader(tx)
+	if err != nil {
+		return types.Transaction{}, err
+	}
+	err = uploader.ConcurrentOnce(ctx, concurrentNum)
+	return *tx, err
+}
+
+func (w *Wallet) getUploader(tx *types.Transaction) (*TransactionUploader, error) {
+	anchor, err := w.Client.GetTransactionAnchor()
+	if err != nil {
+		return nil, err
+	}
+	tx.LastTx = anchor
+	tx.Owner = w.Owner()
+	if err = w.Signer.SignTx(tx); err != nil {
+		return nil, err
+	}
+	return CreateUploader(w.Client, tx, nil)
+}
+
 func (w *Wallet) SendPst(contractId string, target string, qty *big.Int, customTags []types.Tag, speedFactor int64) (types.Transaction, error) {
 	maxQty := big.NewInt(9007199254740991) // swc support max js integer
 	if qty.Cmp(maxQty) > 0 {
diff --git a/wallet_bundle.go b/wallet_bundle.go
index c3b9fe2..b0c9ceb 100644
--- a/wallet_bundle.go
+++ b/wallet_bundle.go
@@ -1,11 +1,12 @@
 package goar
 
 import (
+	"context"
 	"errors"
 	"github.com/everFinance/goar/types"
 )
 
-func (w *Wallet) SendBundleTxSpeedUp(bundleBinary []byte, tags []types.Tag, txSpeed int64) (types.Transaction, error) {
+func (w *Wallet) SendBundleTxSpeedUp(ctx context.Context, concurrentNum int, bundleBinary []byte, tags []types.Tag, txSpeed int64) (types.Transaction, error) {
 	bundleTags := []types.Tag{
 		{Name: "Bundle-Format", Value: "binary"},
 		{Name: "Bundle-Version", Value: "2.0.0"},
@@ -23,9 +24,9 @@ func (w *Wallet) SendBundleTxSpeedUp(bundleBinary []byte, tags []types.Tag, txSp
 
 	txTags := make([]types.Tag, 0)
 	txTags = append(bundleTags, tags...)
-	return w.SendDataSpeedUp(bundleBinary, txTags, txSpeed)
+	return w.SendDataConcurrentSpeedUp(ctx, concurrentNum, bundleBinary, txTags, txSpeed)
 }
 
-func (w *Wallet) SendBundleTx(bundleBinary []byte, tags []types.Tag) (types.Transaction, error) {
-	return w.SendBundleTxSpeedUp(bundleBinary, tags, 0)
+func (w *Wallet) SendBundleTx(ctx context.Context, concurrentNum int, bundleBinary []byte, tags []types.Tag) (types.Transaction, error) {
+	return w.SendBundleTxSpeedUp(ctx, concurrentNum, bundleBinary, tags, 0)
 }