diff --git a/app/controllers/exercise_controller.rb b/app/controllers/exercise_controller.rb
index 8fa5e0230..f19e15ba1 100644
--- a/app/controllers/exercise_controller.rb
+++ b/app/controllers/exercise_controller.rb
@@ -1,15 +1,16 @@
 class ExerciseController < ApplicationController
   layout "base_courses"
 
-  before_filter :find_exercise_and_course, :only => [:create_exercise_question]
-  before_filter :find_course, :only => [:index,:new,:create,:student_exercise_list,:edit]
+  before_filter :find_exercise_and_course, :only => [:create_exercise_question, :edit]
+  before_filter :find_course, :only => [:index,:new,:create,:student_exercise_list]
 
   def index
+    # remove_invalid_exercise(@course)
     @is_teacher = User.current.allowed_to?(:as_teacher,@course)
     if @is_teacher
       exercises = @course.exercises
     else
-      exercises = @course.exercises.where(:exercise_status => 1)
+      exercises = @course.exercises.where(:exercise_status => 2)
     end
     @exercises = paginateHelper exercises,20 #分页
     respond_to do |format|
@@ -46,7 +47,7 @@ class ExerciseController < ApplicationController
         :time => Time.now,
         :end_time => Time.now,
         :publish_time => Time.now,
-        :polls_description => ""
+        :exercise_description => ""
     }
     @exercise = Exercise.create option
     if @exercise
@@ -230,6 +231,10 @@ class ExerciseController < ApplicationController
   end
 
   private
+  def remove_invalid_exercise
+    excercises = @course.exercises
+  end
+
   def find_exercise_and_course
     @exercise = Exercise.find params[:id]
     @course = Course.find @exercise.course_id