diff --git a/commands/sudo.py b/commands/sudo.py
index 9d01e691..b96e1db8 100644
--- a/commands/sudo.py
+++ b/commands/sudo.py
@@ -1,10 +1,103 @@
-from command import CommandRegistry
+import sqlite3
+
+from command import CommandRegistry, split_args
 from commands import core
+from little_shit import get_default_db_path, get_target
 
 __registry__ = cr = CommandRegistry()
 
+_create_table_sql = """CREATE TABLE IF NOT EXISTS blocked_target_list (
+  target TEXT NOT NULL
+)"""
+
+
+def _open_db_conn():
+    conn = sqlite3.connect(get_default_db_path())
+    conn.execute(_create_table_sql)
+    conn.commit()
+    return conn
+
 
 @cr.register('test')
 @cr.restrict(full_command_only=True, superuser_only=True)
 def test(_, ctx_msg):
     core.echo('Your are the superuser!', ctx_msg)
+
+
+@cr.register('block')
+@cr.restrict(full_command_only=True, superuser_only=True)
+@split_args(maxsplit=2)
+def block(args, ctx_msg):
+    def _send_error_msg():
+        core.echo('参数不正确。\n\n正确使用方法：\nsudo.block wx|qq <account-to-block>', ctx_msg)
+
+    if len(args) != 2:
+        _send_error_msg()
+        return
+
+    via, account = args
+    # Get a target using a fake context message
+    target = get_target({
+        'via': via,
+        'type': 'friend_message',
+        'sender_uid': account,
+        'sender_account': account
+    })
+
+    if not target:
+        _send_error_msg()
+        return
+
+    conn = _open_db_conn()
+    conn.execute('INSERT INTO blocked_target_list (target) VALUES (?)', (target,))
+    conn.commit()
+    conn.close()
+    core.echo('成功屏蔽用户 ' + account, ctx_msg)
+
+
+@cr.register('block_list', 'block-list')
+@cr.restrict(full_command_only=True, superuser_only=True)
+def block_list(_, ctx_msg, internal=False):
+    conn = _open_db_conn()
+    cursor = conn.execute('SELECT target FROM blocked_target_list')
+    blocked_targets = list(set([x[0] for x in list(cursor)]))  # Get targets and remove duplications
+    conn.close()
+    if internal:
+        return blocked_targets
+    if blocked_targets:
+        # `t[1:]` to reply user account, without target prefix 'p'.
+        # This is a shit code, and should be changed later sometime.
+        core.echo('已屏蔽的用户：\n' + ', '.join([t[1:] for t in blocked_targets]), ctx_msg)
+    else:
+        core.echo('还没有屏蔽过用户')
+
+
+@cr.register('unblock')
+@cr.restrict(full_command_only=True, superuser_only=True)
+@split_args(maxsplit=2)
+def unblock(args, ctx_msg):
+    def _send_error_msg():
+        core.echo('参数不正确。\n\n正确使用方法：\nsudo.unblock wx|qq <account-to-unblock>', ctx_msg)
+
+    if len(args) != 2:
+        _send_error_msg()
+        return
+
+    via, account = args
+    # Get a target using a fake context message
+    target = get_target({
+        'via': via,
+        'type': 'friend_message',
+        'sender_uid': account,
+        'sender_account': account
+    })
+
+    if not target:
+        _send_error_msg()
+        return
+
+    conn = _open_db_conn()
+    conn.execute('DELETE FROM blocked_target_list WHERE target = ?', (target,))
+    conn.commit()
+    conn.close()
+    core.echo('成功取消屏蔽用户 ' + account, ctx_msg)
diff --git a/filters/intercept_blocked_target_100.py b/filters/intercept_blocked_target_100.py
new file mode 100644
index 00000000..387759f8
--- /dev/null
+++ b/filters/intercept_blocked_target_100.py
@@ -0,0 +1,18 @@
+"""
+This filter intercepts messages from blocked targets (blocked using sudo.block command).
+"""
+
+from commands import sudo
+from filter import as_filter
+from little_shit import get_target
+
+
+@as_filter(priority=100)
+def _filter(ctx_msg):
+    target = get_target(ctx_msg)
+    if not target:
+        return True
+
+    if target in sudo.block_list('', ctx_msg, internal=True):
+        return False
+    return True