diff --git a/weixin-java-miniapp/src/main/java/cn/binarywang/wx/miniapp/api/impl/WxMaImmediateDeliveryServiceImpl.java b/weixin-java-miniapp/src/main/java/cn/binarywang/wx/miniapp/api/impl/WxMaImmediateDeliveryServiceImpl.java
index fa1927ffd..05e8f2e0a 100644
--- a/weixin-java-miniapp/src/main/java/cn/binarywang/wx/miniapp/api/impl/WxMaImmediateDeliveryServiceImpl.java
+++ b/weixin-java-miniapp/src/main/java/cn/binarywang/wx/miniapp/api/impl/WxMaImmediateDeliveryServiceImpl.java
@@ -197,7 +197,7 @@ public class WxMaImmediateDeliveryServiceImpl implements WxMaImmediateDeliverySe
 
   @Override
   public GetDeliveryListResponse getDeliveryList() throws WxErrorException {
-    String responseContent = this.wxMaService.post(InstantDelivery.GET_DELIVERY_LIST_URL,"");
+    String responseContent = this.wxMaService.post(InstantDelivery.GET_DELIVERY_LIST_URL,"{}");
     GetDeliveryListResponse response = GetDeliveryListResponse.fromJson(responseContent);
     if (response.getErrcode() == -1) {
       throw new WxErrorException(WxError.fromJson(responseContent, WxType.MiniApp));