diff --git a/QiniuSDK/QiniuResumableClient.m b/QiniuSDK/QiniuResumableClient.m
index 3a9ecc4..68f475d 100644
--- a/QiniuSDK/QiniuResumableClient.m
+++ b/QiniuSDK/QiniuResumableClient.m
@@ -182,8 +182,13 @@ - (void)mkfile:(NSString *)key
 {
     
     NSString *mimeStr = extra.mimeType == nil ? @"" : [[NSString alloc] initWithFormat:@"/mimetype/%@", [QiniuResumableClient encode:extra.mimeType]];
-    NSString *keyStr = [[NSString alloc] initWithFormat:@"/key/%@", [QiniuResumableClient encode:key]];
-    NSString *callUrl = [[NSString alloc] initWithFormat:@"%@/mkfile/%u%@%@", kQiniuUpHost, (unsigned int)fileSize, mimeStr, keyStr];
+    
+    NSString *callUrl = [[NSString alloc] initWithFormat:@"%@/mkfile/%u%@", kQiniuUpHost, (unsigned int)fileSize, mimeStr];
+    
+    if (key != nil) {
+        NSString *keyStr = [[NSString alloc] initWithFormat:@"/key/%@", [QiniuResumableClient encode:key]];
+        callUrl = [NSString stringWithFormat:@"%@%@", callUrl, keyStr];
+    }
     
     if (extra.params != nil) {
         NSEnumerator *e = [extra.params keyEnumerator];
diff --git a/QiniuSDKTests/QiniuSDKTests.m b/QiniuSDKTests/QiniuSDKTests.m
index 1c6ef6c..c7d5da1 100644
--- a/QiniuSDKTests/QiniuSDKTests.m
+++ b/QiniuSDKTests/QiniuSDKTests.m
@@ -41,7 +41,7 @@ - (void)setUp
     // Prepare the uptoken
     // token with a year, 14.2.23
     _token = @"6UOyH0xzsnOF-uKmsHgpi7AhGWdfvI8glyYV3uPg:m-8jeXMWC-4kstLEHEMCfZAZnWc=:eyJkZWFkbGluZSI6MTQyNDY4ODYxOCwic2NvcGUiOiJ0ZXN0MzY5In0=";
-
+    
     _done = false;
     _progressReceived = false;
 }
@@ -171,6 +171,17 @@ - (void)testResumableUploadSmall
     XCTAssertEqual(_succeed, YES, "ResumableUpload failed, error: %@", _error);
 }
 
+- (void)testResumableUploadWithoutKey
+{
+    QiniuResumableUploader *uploader = [[QiniuResumableUploader alloc] initWithToken:_token];
+    uploader.delegate = self;
+    
+    NSLog(@"resumable upload");
+    [uploader uploadFile:_filePath key:nil extra:nil];
+    [self waitFinish];
+    XCTAssertEqual(_succeed, YES, "ResumableUpload failed, error: %@", _error);
+}
+
   // */
 
 - (void)testResumableUploadWithParam