diff --git a/Storage/Storage/Internal/File/LCAWSUploader.cs b/Storage/Storage/Internal/File/LCAWSUploader.cs
index d5484c9..1c9a731 100644
--- a/Storage/Storage/Internal/File/LCAWSUploader.cs
+++ b/Storage/Storage/Internal/File/LCAWSUploader.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Net;
+using System.IO;
 using System.Net.Http;
 using System.Net.Http.Headers;
 using System.Threading.Tasks;
@@ -7,20 +8,20 @@ using LeanCloud.Common;
 
 namespace LeanCloud.Storage.Internal.File {
     internal class LCAWSUploader {
-        string uploadUrl;
+        private string uploadUrl;
 
-        string mimeType;
+        private string mimeType;
 
-        byte[] data;
+        private Stream stream;
 
-        internal LCAWSUploader(string uploadUrl, string mimeType, byte[] data) {
+        internal LCAWSUploader(string uploadUrl, string mimeType, Stream stream) {
             this.uploadUrl = uploadUrl;
             this.mimeType = mimeType;
-            this.data = data;
+            this.stream = stream;
         }
 
         internal async Task Upload(Action<long, long> onProgress) {
-            LCProgressableStreamContent content = new LCProgressableStreamContent(new ByteArrayContent(data), onProgress);
+            LCProgressableStreamContent content = new LCProgressableStreamContent(new StreamContent(stream), onProgress);
 
             HttpRequestMessage request = new HttpRequestMessage {
                 RequestUri = new Uri(uploadUrl),
diff --git a/Storage/Storage/Internal/File/LCQiniuUploader.cs b/Storage/Storage/Internal/File/LCQiniuUploader.cs
index 69459ff..29ea743 100644
--- a/Storage/Storage/Internal/File/LCQiniuUploader.cs
+++ b/Storage/Storage/Internal/File/LCQiniuUploader.cs
@@ -1,32 +1,32 @@
 using System;
+using System.IO;
 using System.Threading.Tasks;
 using System.Net;
 using System.Net.Http;
-using System.Net.Http.Headers;
 using LeanCloud.Common;
 
 namespace LeanCloud.Storage.Internal.File {
     internal class LCQiniuUploader {
-        string uploadUrl;
+        private string uploadUrl;
 
-        string token;
+        private string token;
 
-        string key;
+        private string key;
 
-        byte[] data;
+        private Stream stream;
 
-        internal LCQiniuUploader(string uploadUrl, string token, string key, byte[] data) {
+        internal LCQiniuUploader(string uploadUrl, string token, string key, Stream stream) {
             this.uploadUrl = uploadUrl;
             this.token = token;
             this.key = key;
-            this.data = data;
+            this.stream = stream;
         }
 
         internal async Task Upload(Action<long, long> onProgress) {
             MultipartFormDataContent dataContent = new MultipartFormDataContent();
             dataContent.Add(new StringContent(key), "key");
             dataContent.Add(new StringContent(token), "token");
-            dataContent.Add(new ByteArrayContent(data), "file");
+            dataContent.Add(new StreamContent(stream), "file");
 
             LCProgressableStreamContent content = new LCProgressableStreamContent(dataContent, onProgress);
 
diff --git a/Storage/Storage/LCFile.cs b/Storage/Storage/LCFile.cs
index 8e504f9..a27db7b 100644
--- a/Storage/Storage/LCFile.cs
+++ b/Storage/Storage/LCFile.cs
@@ -4,7 +4,6 @@ using System.Collections.Generic;
 using System.Threading.Tasks;
 using LeanCloud.Storage.Internal.File;
 using LeanCloud.Storage.Internal.Object;
-using LeanCloud.Common;
 
 namespace LeanCloud.Storage {
     public class LCFile : LCObject {
@@ -42,7 +41,7 @@ namespace LeanCloud.Storage {
             }
         }
 
-        readonly byte[] data;
+        readonly Stream stream;
 
         public LCFile() : base(CLASS_NAME) {
             MetaData = new Dictionary<string, object>();
@@ -50,13 +49,13 @@ namespace LeanCloud.Storage {
 
         public LCFile(string name, byte[] bytes) : this() {
             Name = name;
-            data = bytes;
+            stream = new MemoryStream(bytes);
         }
 
         public LCFile(string name, string path) : this() {
             Name = name;
             MimeType = LCMimeTypeMap.GetMimeType(path);
-            data = File.ReadAllBytes(path);
+            stream = new FileStream(path, FileMode.Open);
         }
 
         public LCFile(string name, Uri url) : this() {
@@ -82,11 +81,11 @@ namespace LeanCloud.Storage {
                 try {
                     if (provider == "s3") {
                         // AWS
-                        LCAWSUploader uploader = new LCAWSUploader(uploadUrl, MimeType, data);
+                        LCAWSUploader uploader = new LCAWSUploader(uploadUrl, MimeType, stream);
                         await uploader.Upload(onProgress);
                     } else if (provider == "qiniu") {
                         // Qiniu
-                        LCQiniuUploader uploader = new LCQiniuUploader(uploadUrl, token, key, data);
+                        LCQiniuUploader uploader = new LCQiniuUploader(uploadUrl, token, key, stream);
                         await uploader.Upload(onProgress);
                     } else {
                         throw new Exception($"{provider} is not support.");