diff --git a/account/migrations/0012_userprofile_language.py b/account/migrations/0012_userprofile_language.py
new file mode 100644
index 00000000..a8794886
--- /dev/null
+++ b/account/migrations/0012_userprofile_language.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.4 on 2018-07-15 02:06
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('account', '0011_auto_20180501_0456'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='userprofile',
+            name='language',
+            field=models.TextField(null=True),
+        ),
+    ]
diff --git a/account/models.py b/account/models.py
index b2b2c21d..eac1a62d 100644
--- a/account/models.py
+++ b/account/models.py
@@ -94,6 +94,7 @@ class UserProfile(models.Model):
     github = models.TextField(null=True)
     school = models.TextField(null=True)
     major = models.TextField(null=True)
+    language = models.TextField(null=True)
     # for ACM
     accepted_number = models.IntegerField(default=0)
     # for OI
diff --git a/account/serializers.py b/account/serializers.py
index 710de0ff..21ae24aa 100644
--- a/account/serializers.py
+++ b/account/serializers.py
@@ -105,6 +105,7 @@ class EditUserProfileSerializer(serializers.Serializer):
     github = serializers.CharField(max_length=64, allow_blank=True, required=False)
     school = serializers.CharField(max_length=64, allow_blank=True, required=False)
     major = serializers.CharField(max_length=64, allow_blank=True, required=False)
+    language = serializers.CharField(max_length=32, allow_blank=True, required=False)
 
 
 class ApplyResetPasswordSerializer(serializers.Serializer):
diff --git a/account/tests.py b/account/tests.py
index 7ca7e810..65e765da 100644
--- a/account/tests.py
+++ b/account/tests.py
@@ -252,12 +252,13 @@ class UserProfileAPITest(APITestCase):
 
     def test_update_profile(self):
         self.create_user("test", "test123")
-        update_data = {"real_name": "zemal", "submission_number": 233}
+        update_data = {"real_name": "zemal", "submission_number": 233, "language": "en-US"}
         resp = self.client.put(self.url, data=update_data)
         self.assertSuccess(resp)
         data = resp.data["data"]
         self.assertEqual(data["real_name"], "zemal")
         self.assertEqual(data["submission_number"], 0)
+        self.assertEqual(data["language"], "en-US")
 
 
 class TwoFactorAuthAPITest(APITestCase):
diff --git a/deploy/requirements.txt b/deploy/requirements.txt
index 554250a8..75827ffd 100644
--- a/deploy/requirements.txt
+++ b/deploy/requirements.txt
@@ -12,8 +12,8 @@ qrcode
 flake8-coding
 requests
 django-redis
-psycopg2
+psycopg2-binary
 gunicorn
 jsonfield
 XlsxWriter
-raven
\ No newline at end of file
+raven
diff --git a/docs/data.json b/docs/data.json
index d9dede59..854d63be 100644
--- a/docs/data.json
+++ b/docs/data.json
@@ -1,11 +1,21 @@
 {
   "update": [
+    {
+      "version": "2018-07-15",
+      "level": "Recommend",
+      "title": "Update at 2018-07-15",
+      "details": [
+        "Add Traditional Chinese, by <a href='https://github.com/QingdaoU/OnlineJudgeFE/pull/27'>xdavidwu</a>",
+        "Fix a bug in the navigation bar",
+        "Move language switch to profile settings page"
+      ]
+    },
     {
       "version": "2018-06-02",
       "level": "Recommend",
       "title": "Update at 2018-06-02",
       "details": [
-        "Add Chinese, by <a href='https://github.com/QingdaoU/OnlineJudgeFE/issues/22'>hirCodd</a>",
+        "Add Simple Chinese, by <a href='https://github.com/QingdaoU/OnlineJudgeFE/issues/22'>hirCodd</a>",
         "Integrate with katex",
         "Update libraries to latest version",
         "The first page in management is changed to dashboard"