diff --git a/LiveQuery/LiveQuery/Internal/LCLiveQueryConnection.cs b/LiveQuery/LiveQuery/Internal/LCLiveQueryConnection.cs
index d2e4466..d11a33e 100644
--- a/LiveQuery/LiveQuery/Internal/LCLiveQueryConnection.cs
+++ b/LiveQuery/LiveQuery/Internal/LCLiveQueryConnection.cs
@@ -136,9 +136,9 @@ namespace LeanCloud.LiveQuery.Internal {
             await client.Close();
         }
 
-        private void OnClientMessage(byte[] bytes) {
+        private void OnClientMessage(byte[] bytes, int length) {
             try {
-                string json = Encoding.UTF8.GetString(bytes);
+                string json = Encoding.UTF8.GetString(bytes, 0, length);
                 Dictionary<string, object> msg = JsonConvert.DeserializeObject<Dictionary<string, object>>(json,
                     LCJsonConverter.Default);
                 LCLogger.Debug($"{id} <= {json}");
diff --git a/Realtime/Realtime/Internal/Connection/LCConnection.cs b/Realtime/Realtime/Internal/Connection/LCConnection.cs
index 8e3d1d5..5716a74 100644
--- a/Realtime/Realtime/Internal/Connection/LCConnection.cs
+++ b/Realtime/Realtime/Internal/Connection/LCConnection.cs
@@ -160,9 +160,9 @@ namespace LeanCloud.Realtime.Internal.Connection {
             }
         }
 
-        private void OnMessage(byte[] bytes) {
+        private void OnMessage(byte[] bytes, int length) {
             try {
-                GenericCommand command = GenericCommand.Parser.ParseFrom(bytes);
+                GenericCommand command = GenericCommand.Parser.ParseFrom(bytes, 0, length);
                 LCLogger.Debug($"{id} <= {FormatCommand(command)}");
                 if (command.HasI) {
                     // 应答
diff --git a/Realtime/Realtime/Internal/WebSocket/LCWebSocketClient.cs b/Realtime/Realtime/Internal/WebSocket/LCWebSocketClient.cs
index 1a6e5e4..6c6456f 100644
--- a/Realtime/Realtime/Internal/WebSocket/LCWebSocketClient.cs
+++ b/Realtime/Realtime/Internal/WebSocket/LCWebSocketClient.cs
@@ -6,13 +6,15 @@ using System.Text;
 namespace LeanCloud.Realtime.Internal.WebSocket {
     public class LCWebSocketClient {
         // .net standard 2.0 好像在拼合 Frame 时有 bug，所以将这个值调整大一些
-        private const int RECV_BUFFER_SIZE = 1024 * 5;
+        private const int SEND_BUFFER_SIZE = 1024 * 5;
+        private const int RECV_BUFFER_SIZE = 1024 * 8;
+        private const int MSG_BUFFER_SIZE = 1024 * 10;
 
         private const int CLOSE_TIMEOUT = 5000;
 
         private const int CONNECT_TIMEOUT = 10000;
 
-        public Action<byte[]> OnMessage;
+        public Action<byte[], int> OnMessage;
 
         public Action OnClose;
 
@@ -23,6 +25,7 @@ namespace LeanCloud.Realtime.Internal.WebSocket {
             LCLogger.Debug($"Connecting WebSocket: {server}");
             Task timeoutTask = Task.Delay(CONNECT_TIMEOUT);
             ws = new ClientWebSocket();
+            ws.Options.SetBuffer(RECV_BUFFER_SIZE, SEND_BUFFER_SIZE);
             if (!string.IsNullOrEmpty(subProtocol)) {
                 ws.Options.AddSubProtocol(subProtocol);
             }
@@ -78,10 +81,12 @@ namespace LeanCloud.Realtime.Internal.WebSocket {
         }
 
         private async Task StartReceive() {
-            byte[] buffer = new byte[RECV_BUFFER_SIZE];
+            byte[] recvBuffer = new byte[RECV_BUFFER_SIZE];
+            byte[] msgBuffer = new byte[MSG_BUFFER_SIZE];
+            int offset = 0;
             try {
                 while (ws.State == WebSocketState.Open) {
-                    WebSocketReceiveResult result = await ws.ReceiveAsync(new ArraySegment<byte>(buffer), default);
+                    WebSocketReceiveResult result = await ws.ReceiveAsync(new ArraySegment<byte>(recvBuffer), default);
                     if (result.MessageType == WebSocketMessageType.Close) {
                         LCLogger.Debug($"Receive Closed: {result.CloseStatus}");
                         if (ws.State == WebSocketState.CloseReceived) {
@@ -98,9 +103,18 @@ namespace LeanCloud.Realtime.Internal.WebSocket {
                     } else {
                         // 拼合 WebSocket Message
                         int length = result.Count;
-                        byte[] data = new byte[length];
-                        Array.Copy(buffer, data, length);
-                        OnMessage?.Invoke(data);
+                        if (offset + length > msgBuffer.Length) {
+                            // 反序列化数组大小不够，则以 2x 扩充
+                            byte[] newBuffer = new byte[msgBuffer.Length * 2];
+                            Array.Copy(msgBuffer, newBuffer, msgBuffer.Length);
+                            msgBuffer = newBuffer;
+                        }
+                        Array.Copy(recvBuffer, 0, msgBuffer, offset, length);
+                        offset += length;
+                        if (result.EndOfMessage) {
+                            OnMessage?.Invoke(msgBuffer, offset);
+                            offset = 0;
+                        }
                     }
                 }
             } catch (Exception e) {