diff --git a/static/src/js/app/admin/problem/addProblem.js b/static/src/js/app/admin/problem/addProblem.js
index c6e49ca..103396b 100644
--- a/static/src/js/app/admin/problem/addProblem.js
+++ b/static/src/js/app/admin/problem/addProblem.js
@@ -13,6 +13,10 @@ require(["jquery", "avalon", "editor", "uploader", "bsAlert", "csrfToken", "tagE
                             bsAlert("题目描述不能为空!");
                             return false;
                         }
+                        if (vm.timeLimit < 100 || vm.timeLimit > 5000) {
+                            bsAlert("保证时间限制是一个100-5000的合法整数");
+                            return false;
+                        }
                         if (vm.samples.length == 0) {
                             bsAlert("请至少添加一组样例!");
                             return false;
diff --git a/static/src/js/app/admin/problem/editProblem.js b/static/src/js/app/admin/problem/editProblem.js
index a746d7a..416d86f 100644
--- a/static/src/js/app/admin/problem/editProblem.js
+++ b/static/src/js/app/admin/problem/editProblem.js
@@ -14,8 +14,8 @@ require(["jquery", "avalon", "editor", "uploader", "bsAlert", "csrfToken", "tagE
                             bsAlert("题目描述不能为空!");
                             return false;
                         }
-                        if (vm.timeLimit < 1000 || vm.timeLimit > 5000) {
-                            bsAlert("保证时间限制是一个1000-5000的合法整数");
+                        if (vm.timeLimit < 100 || vm.timeLimit > 5000) {
+                            bsAlert("保证时间限制是一个100-5000的合法整数");
                             return false;
                         }
                         if (vm.samples.length == 0) {
diff --git a/template/src/admin/problem/add_problem.html b/template/src/admin/problem/add_problem.html
index 70bd524..37c48bb 100644
--- a/template/src/admin/problem/add_problem.html
+++ b/template/src/admin/problem/add_problem.html
@@ -18,7 +18,7 @@
         <div class="col-md-3">
             <div class="form-group"><label>时间限制(ms)</label>
                 <input type="number" name="timeLimit" class="form-control" ms-duplex="timeLimit"
-                       data-error="请输入时间限制(保证是一个1000-5000的合法整数)" required>
+                       data-error="请输入时间限制(保证是一个100-5000的合法整数)" required>
                 <div class="help-block with-errors"></div>
             </div>
         </div>
@@ -31,8 +31,12 @@
         </div>
         <div class="col-md-3">
             <div class="form-group"><label>难度</label>
-                <input type="number" name="difficulty" class="form-control" ms-duplex="difficulty"
-                       data-error="请输入难度(保证是一个合法整数)" required>
+                <select name="difficulty" class="form-control" ms-duplex="difficulty"
+                       data-error="请选择难度" required>
+                    <option value="1" selected="selected">简单</option>
+                    <option value="2">中等</option>
+                    <option value="3">难</option>
+                </select>
                 <div class="help-block with-errors"></div>
             </div>
         </div>
diff --git a/template/src/admin/problem/edit_problem.html b/template/src/admin/problem/edit_problem.html
index d2587b3..d7c9743 100644
--- a/template/src/admin/problem/edit_problem.html
+++ b/template/src/admin/problem/edit_problem.html
@@ -24,7 +24,7 @@
         <div class="col-md-3">
             <div class="form-group"><label>时间限制(ms)</label>
                 <input type="number" name="timeLimit" class="form-control" ms-duplex="timeLimit"
-                       data-error="请输入时间限制(保证是一个1000-5000的合法整数)" required>
+                       data-error="请输入时间限制(保证是一个100-5000的合法整数)" required>
                 <div class="help-block with-errors"></div>
             </div>
         </div>
@@ -37,8 +37,12 @@
         </div>
         <div class="col-md-3">
             <div class="form-group"><label>难度</label>
-                <input type="number" name="difficulty" class="form-control" ms-duplex="difficulty"
-                       data-error="请输入难度(保证是一个合法整数)" required>
+                <select name="difficulty" class="form-control" ms-duplex="difficulty"
+                       data-error="请选择难度" required>
+                    <option value="1">简单</option>
+                    <option value="2">中等</option>
+                    <option value="3">难</option>
+                </select>
                 <div class="help-block with-errors"></div>
             </div>
         </div>
diff --git a/template/src/oj/problem/problem_list.html b/template/src/oj/problem/problem_list.html
index 878ded4..0af942d 100644
--- a/template/src/oj/problem/problem_list.html
+++ b/template/src/oj/problem/problem_list.html
@@ -31,7 +31,16 @@
                                 <th><span class="glyphicon glyphicon-ok ac-flag"></span></th>
                                 <th scope="row"><a href="/problem/{{ item.id }}/">{{ item.id }}</a></th>
                                 <td><a href="/problem/{{ item.id }}/">{{ item.title }}</a></td>
-                                <td>{{ item.difficulty }}</td>
+                                <td>
+                                    {% ifequal item.difficulty 1 %}
+                                        简单
+                                    {% else %}
+                                        {% ifequal item.difficulty 2 %}
+                                            中等
+                                        {% else %}
+                                            难
+                                        {% endifequal %}
+                                    {% endifequal %}</td>
                                 <td>{{ item|accepted_radio }}</td>
                             </tr>
                         {% endfor %}
@@ -65,10 +74,11 @@
                     </div>
                     <ul class="list-group">
                         {% for item in tags %}
-                        <li class="list-group-item problem-tag" onclick="location.href='/problems/?tag={{ item.name }}'">
-                            <span class="badge">{{ item.problem_number }}</span>
-                            {{ item.name }}
-                        </li>
+                            <li class="list-group-item problem-tag"
+                                onclick="location.href='/problems/?tag={{ item.name }}'">
+                                <span class="badge">{{ item.problem_number }}</span>
+                                {{ item.name }}
+                            </li>
                         {% endfor %}
                     </ul>
                 </div>