diff --git a/shadowsocks/asyncdns.py b/shadowsocks/asyncdns.py
index 98db3bb..899fec9 100644
--- a/shadowsocks/asyncdns.py
+++ b/shadowsocks/asyncdns.py
@@ -280,7 +280,11 @@ class DNSResolver(object):
         if type(black_hostname_list) != list:
             self._black_hostname_list = []
         else:
-            self._black_hostname_list = black_hostname_list
+            self._black_hostname_list = list(map(
+                (lambda t: t if type(t) == bytes else t.encode('utf8')),
+                black_hostname_list
+            ))
+        print('black_hostname_list init as : ' + str(self._black_hostname_list))
         self._sock = None
         self._servers = None
         self._parse_resolv()
@@ -474,6 +478,7 @@ class DNSResolver(object):
             callback((hostname, ip), None)
         elif hostname in self._black_hostname_list:
             callback(None, Exception('hostname <%s> in the black hostname list' % hostname))
+            return
         else:
             if not is_valid_hostname(hostname):
                 callback(None, Exception('invalid hostname: %s' % hostname))
@@ -515,7 +520,10 @@ class DNSResolver(object):
 
 
 def test():
-    dns_resolver = DNSResolver()
+    black_hostname_list = [
+        'baidu.com'
+    ]
+    dns_resolver = DNSResolver(black_hostname_list=black_hostname_list)
     loop = eventloop.EventLoop()
     dns_resolver.add_to_loop(loop)
 
@@ -541,6 +549,7 @@ def test():
 
     dns_resolver.resolve(b'google.com', make_callback())
     dns_resolver.resolve('google.com', make_callback())
+    dns_resolver.resolve('baidu.com', make_callback())
     dns_resolver.resolve('example.com', make_callback())
     dns_resolver.resolve('ipv6.google.com', make_callback())
     dns_resolver.resolve('www.facebook.com', make_callback())
@@ -556,8 +565,24 @@ def test():
                          'ooooooooooooooooooooooooooooooooooooooooooooooooooo'
                          'ooooooooooooooooooooooooooooooooooooooooooooooooooo'
                          'long.hostname', make_callback())
-
     loop.run()
+    # test black_hostname_list
+    dns_resolver = DNSResolver(black_hostname_list=[])
+    assert type(dns_resolver._black_hostname_list) == list
+    assert dns_resolver._black_hostname_list.__len__() == 0
+    dns_resolver.close()
+    dns_resolver = DNSResolver(black_hostname_list=123)
+    assert type(dns_resolver._black_hostname_list) == list
+    assert dns_resolver._black_hostname_list.__len__() == 0
+    dns_resolver.close()
+    dns_resolver = DNSResolver(black_hostname_list=None)
+    assert type(dns_resolver._black_hostname_list) == list
+    assert dns_resolver._black_hostname_list.__len__() == 0
+    dns_resolver.close()
+    dns_resolver = DNSResolver()
+    assert type(dns_resolver._black_hostname_list) == list
+    assert dns_resolver._black_hostname_list.__len__() == 0
+    dns_resolver.close()
 
 
 if __name__ == '__main__':