diff --git a/app/views/bids/_homework.html.erb b/app/views/bids/_homework.html.erb
index 0cb1ff7cc..0272f2c63 100644
--- a/app/views/bids/_homework.html.erb
+++ b/app/views/bids/_homework.html.erb
@@ -59,6 +59,17 @@
                 }
             );
         }
+
+        $(window).scroll(function(){
+            //获取窗口的滚动条的垂直位置
+            var s = $(window).scrollTop();
+            //当窗口的滚动条的垂直位置大于页面的最小高度时，让返回顶部元素渐现，否则渐隐
+            if( s > 600){
+                $("#gotoTop").fadeIn(100);
+            }else{
+                $("#gotoTop").fadeOut(200);
+            };
+        });
 	</script>
 </div>
 <div id='bidding_project_list'>
diff --git a/app/views/homework_attach/_homeworks_list.html.erb b/app/views/homework_attach/_homeworks_list.html.erb
index 689eaa08b..08ea9434d 100644
--- a/app/views/homework_attach/_homeworks_list.html.erb
+++ b/app/views/homework_attach/_homeworks_list.html.erb
@@ -36,7 +36,7 @@
 <% end %>
 <div class="cl"></div>
 
-<div class="to_top" onclick="javascript:scroll(0,0);">
+<div class="to_top" onclick="javascript:scroll(0,0);" id="gotoTop">
     返<br/>回<br/>顶<br/>部
 </div>
 <div class="cl"></div>