diff --git a/app/controllers/student_work_controller.rb b/app/controllers/student_work_controller.rb
index 9597a35cf..424ddd71f 100644
--- a/app/controllers/student_work_controller.rb
+++ b/app/controllers/student_work_controller.rb
@@ -890,7 +890,7 @@ class StudentWorkController < ApplicationController
       @homework.save
     end
 
-    unless homework_detail_manual.absence_penalty.to_s == params[:absence_penalty].to_s
+    if params[:absence_penalty] && homework_detail_manual.absence_penalty.to_s != params[:absence_penalty].to_s
       homework_detail_manual.absence_penalty = params[:absence_penalty]
       if homework_detail_manual.comment_status == 3 #当前作业处于匿评结束状态，修改缺评扣分才会修改每个作品应扣分的值
         work_ids = "(" + @homework.student_works.map(&:id).join(",") + ")"
diff --git a/app/views/student_work/_set_score_rule_detail.html.erb b/app/views/student_work/_set_score_rule_detail.html.erb
index c8451e478..28ca9e785 100644
--- a/app/views/student_work/_set_score_rule_detail.html.erb
+++ b/app/views/student_work/_set_score_rule_detail.html.erb
@@ -4,10 +4,12 @@
     <span class="f14 fontGrey3 mr10">迟交扣分</span>
     <input type="text" name="late_penalty" id="late_penalty_num" placeholder="请输入0-50数值" class=" markInput"  value="<%= homework.late_penalty%>" onkeyup="check_late_penalty('late_penalty_num')"/>
   </div>
-  <div>
-    <span class="f14 fontGrey3 mr10">缺评扣分</span>
-    <input type="text" name="absence_penalty" id="absence_penalty_num" placeholder="请输入0-50数值" class="markInput" value="<%= homework.homework_detail_manual.absence_penalty%>" onkeyup="check_late_penalty('absence_penalty_num')"/>
-  </div>
+  <% if homework.anonymous_comment == 0 %>
+      <div>
+        <span class="f14 fontGrey3 mr10">缺评扣分</span>
+        <input type="text" name="absence_penalty" id="absence_penalty_num" placeholder="请输入0-50数值" class="markInput" value="<%= homework.homework_detail_manual.absence_penalty%>" onkeyup="check_late_penalty('absence_penalty_num')"/>
+      </div>
+  <% end %>
 
   <% if homework.homework_type == 2%>
       <div>
diff --git a/public/javascripts/course.js b/public/javascripts/course.js
index 0b39a3929..46b8b0e54 100644
--- a/public/javascripts/course.js
+++ b/public/javascripts/course.js
@@ -114,7 +114,7 @@ function regex_course_class_period()
     }
     else
     {
-        $("#course_class_period_notice").html("学时总数必须为数字");
+        $("#course_class_period_notice").html("学时总数必须为正整数");
         $("#course_class_period_notice").show();
         return false;
     }
@@ -1431,4 +1431,4 @@ function submit_course_feedback() {
 
 function show_more_tool(){
     $('#navContentCourse').css('display', 'block');
-}
\ No newline at end of file
+}