diff --git a/config/client.go b/config/client.go
index 6ca2c2073..c9c549685 100644
--- a/config/client.go
+++ b/config/client.go
@@ -44,7 +44,9 @@ import (
 
 const (
 	// DefStoreLivenessTimeout is the default value for store liveness timeout.
-	DefStoreLivenessTimeout = "1s"
+	DefStoreLivenessTimeout      = "1s"
+	DefGrpcInitialWindowSize     = 1 << 27 // 128MiB
+	DefGrpcInitialConnWindowSize = 1 << 27 // 128MiB
 )
 
 // TiKVClient is the config for tikv client.
@@ -62,6 +64,10 @@ type TiKVClient struct {
 	GrpcCompressionType string `toml:"grpc-compression-type" json:"grpc-compression-type"`
 	// GrpcSharedBufferPool is the flag to control whether to share the buffer pool in the TiKV gRPC clients.
 	GrpcSharedBufferPool bool `toml:"grpc-shared-buffer-pool" json:"grpc-shared-buffer-pool"`
+	// GrpcInitialWindowSize is the value for initial window size on a stream.
+	GrpcInitialWindowSize int32 `toml:"grpc-initial-window-size" json:"grpc-initial-window-size"`
+	// GrpcInitialConnWindowSize is the value for initial window size on a connection.
+	GrpcInitialConnWindowSize int32 `toml:"grpc-initial-conn-window-size" json:"grpc-initial-conn-window-size"`
 	// CommitTimeout is the max time which command 'commit' will wait.
 	CommitTimeout string      `toml:"commit-timeout" json:"commit-timeout"`
 	AsyncCommit   AsyncCommit `toml:"async-commit" json:"async-commit"`
@@ -130,12 +136,14 @@ type CoprocessorCache struct {
 // DefaultTiKVClient returns default config for TiKVClient.
 func DefaultTiKVClient() TiKVClient {
 	return TiKVClient{
-		GrpcConnectionCount:  4,
-		GrpcKeepAliveTime:    10,
-		GrpcKeepAliveTimeout: 3,
-		GrpcCompressionType:  "none",
-		GrpcSharedBufferPool: false,
-		CommitTimeout:        "41s",
+		GrpcConnectionCount:       4,
+		GrpcKeepAliveTime:         10,
+		GrpcKeepAliveTimeout:      3,
+		GrpcCompressionType:       "none",
+		GrpcSharedBufferPool:      false,
+		GrpcInitialWindowSize:     DefGrpcInitialWindowSize,
+		GrpcInitialConnWindowSize: DefGrpcInitialConnWindowSize,
+		CommitTimeout:             "41s",
 		AsyncCommit: AsyncCommit{
 			// FIXME: Find an appropriate default limit.
 			KeysLimit:         256,
diff --git a/internal/client/client.go b/internal/client/client.go
index 9bed1129f..31d837b57 100644
--- a/internal/client/client.go
+++ b/internal/client/client.go
@@ -90,12 +90,6 @@ const (
 	MaxWriteExecutionTime = ReadTimeoutShort - 10*time.Second
 )
 
-// Grpc window size
-const (
-	GrpcInitialWindowSize     = 1 << 30
-	GrpcInitialConnWindowSize = 1 << 30
-)
-
 // forwardMetadataKey is the key of gRPC metadata which represents a forwarded request.
 const forwardMetadataKey = "tikv-forwarded-host"
 
@@ -320,8 +314,8 @@ func (a *connArray) Init(addr string, security config.Security, idleNotify *uint
 
 		opts = append([]grpc.DialOption{
 			opt,
-			grpc.WithInitialWindowSize(GrpcInitialWindowSize),
-			grpc.WithInitialConnWindowSize(GrpcInitialConnWindowSize),
+			grpc.WithInitialWindowSize(cfg.TiKVClient.GrpcInitialWindowSize),
+			grpc.WithInitialConnWindowSize(cfg.TiKVClient.GrpcInitialConnWindowSize),
 			grpc.WithUnaryInterceptor(unaryInterceptor),
 			grpc.WithStreamInterceptor(streamInterceptor),
 			grpc.WithDefaultCallOptions(callOptions...),
diff --git a/internal/locate/store_cache.go b/internal/locate/store_cache.go
index fd8a4fc5a..235cbd0a1 100644
--- a/internal/locate/store_cache.go
+++ b/internal/locate/store_cache.go
@@ -28,7 +28,6 @@ import (
 	"github.com/pkg/errors"
 	"github.com/tikv/client-go/v2/config"
 	"github.com/tikv/client-go/v2/config/retry"
-	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/logutil"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
@@ -734,8 +733,8 @@ func createKVHealthClient(ctx context.Context, addr string) (*grpc.ClientConn, h
 		ctx,
 		addr,
 		opt,
-		grpc.WithInitialWindowSize(client.GrpcInitialWindowSize),
-		grpc.WithInitialConnWindowSize(client.GrpcInitialConnWindowSize),
+		grpc.WithInitialWindowSize(cfg.TiKVClient.GrpcInitialWindowSize),
+		grpc.WithInitialConnWindowSize(cfg.TiKVClient.GrpcInitialConnWindowSize),
 		grpc.WithConnectParams(grpc.ConnectParams{
 			Backoff: backoff.Config{
 				BaseDelay:  100 * time.Millisecond, // Default was 1s.