diff --git a/mia_core/models.py b/mia_core/models.py
index 71a8362..75c5fd6 100644
--- a/mia_core/models.py
+++ b/mia_core/models.py
@@ -1,3 +1,107 @@
+# The core application of the Mia project.
+#   by imacat <imacat@mail.imacat.idv.tw>, 2020/6/29
+
+#  Copyright (c) 2020 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+"""The data models of the mia core application.
+
+"""
+
 from django.db import models
 
-# Create your models here.
+
+class Country(models.Model):
+    """A country."""
+    sn = models.PositiveIntegerField(primary_key=True)
+    code = models.CharField(max_length=2, unique=True)
+    name_en = models.CharField(max_length=64)
+    name_zhtw = models.CharField(max_length=32, null=True)
+    name_zhcn = models.CharField(max_length=32, null=True)
+    is_special = models.BooleanField(
+        default=False, db_column="special")
+    created_at = models.DateTimeField(
+        auto_now_add=True, db_column="created")
+    created_by = models.ForeignKey(
+        "User", on_delete=models.PROTECT,
+        db_column="createdby", related_name="created_countries")
+    updated_at = models.DateTimeField(
+        auto_now_add=True, db_column="updated")
+    updated_by = models.ForeignKey(
+        "User", on_delete=models.PROTECT,
+        db_column="updatedby", related_name="updated_countries")
+
+    def __str__(self):
+        """Returns the string representation of this country."""
+        return self.code.__str__() + " " + self.name_zhtw.__str__()
+
+    class Meta:
+        db_table = "countries"
+        ordering = ["code"]
+
+
+class User(models.Model):
+    """A user."""
+    sn = models.PositiveIntegerField(primary_key=True)
+    login_id = models.CharField(max_length=32, unique=True, db_column="id")
+    password = models.CharField(max_length=32, db_column="passwd")
+    name = models.CharField(max_length=32)
+    is_disabled = models.BooleanField(
+        default=False, db_column="disabled")
+    is_deleted = models.BooleanField(
+        default=False, db_column="deleted")
+    language = models.CharField(max_length=6, null=True, db_column="lang")
+    visits = models.PositiveSmallIntegerField(null=True)
+    visited_at = models.DateTimeField(null=True, db_column="visited")
+    visited_ip = models.GenericIPAddressField(null=True, db_column="ip")
+    visited_host = models.CharField(max_length=128, null=True, db_column="host")
+    visited_country = models.ForeignKey(
+        Country, on_delete=models.PROTECT, null=True,
+        db_column="ct", to_field="code", related_name="users")
+    created_at = models.DateTimeField(
+        auto_now_add=True, db_column="created")
+    created_by = models.ForeignKey(
+        "self", on_delete=models.PROTECT,
+        db_column="createdby", related_name="created_users")
+    updated_at = models.DateTimeField(
+        auto_now_add=True, db_column="updated")
+    updated_by = models.ForeignKey(
+        "self", on_delete=models.PROTECT,
+        db_column="updatedby", related_name="updated_users")
+    REQUIRED_FIELDS = ["sn", "name"]
+    USERNAME_FIELD = "login_id"
+
+    @property
+    def is_anonymous(self):
+        return False
+
+    @property
+    def is_authenticated(self):
+        return True
+
+    def set_password(self):
+        pass
+
+    def check_password(self):
+        pass
+
+    def __str__(self):
+        """Returns the string representation of this user."""
+        return "%s(%s)" % (
+            self.name.__str__(), self.login_id.__str__())
+
+    class Meta:
+        db_table = "users"
+        app_label = "mia_core"
+        ordering = ["login_id"]