diff --git a/objwrapper/alioss.py b/objwrapper/alioss.py
index 3cafb4c..94a1364 100644
--- a/objwrapper/alioss.py
+++ b/objwrapper/alioss.py
@@ -1,5 +1,6 @@
 import http.client
 import oss2
+from objwrapper.exceptions import InvalidConfigError
 
 # set log level to WARNING
 # the api set_file_logger exists after oss2 2.6.0, which has a lot of 'INFO' log
@@ -10,11 +11,16 @@
     pass
 
 class OSSConf(object):
-    def __init__(self, key_id, key, bucket_name, host, use_https):
+    def __init__(self, key_id, key, bucket_name, host, region, use_https):
+        if not host and not region:
+            raise InvalidConfigError('endpoint and region are not configured')
+        self.host = host
+        if not host:
+            self.host = 'oss-cn-%s-internal.aliyuncs.com' % region
         self.key_id = key_id
         self.key = key
         self.bucket_name = bucket_name
-        self.host = host
+        self.region = region
         self.use_https = use_https
 
 class SeafOSSClient(object):
diff --git a/objwrapper/exceptions.py b/objwrapper/exceptions.py
new file mode 100644
index 0000000..1f0ae0f
--- /dev/null
+++ b/objwrapper/exceptions.py
@@ -0,0 +1,16 @@
+#coding: UTF-8
+
+class ObjWrapperException(Exception):
+    def __init__(self, msg):
+        Exception.__init__(self)
+        self.msg = str(msg)
+
+    def __str__(self):
+        return self.msg
+
+class InvalidConfigError(ObjWrapperException):
+    '''This Exception is rasied when error happens during parsing
+    seafile.conf
+
+    '''
+    pass
diff --git a/objwrapper/s3.py b/objwrapper/s3.py
index ca28e71..2705748 100644
--- a/objwrapper/s3.py
+++ b/objwrapper/s3.py
@@ -1,8 +1,11 @@
 import boto3
 from botocore.exceptions import ClientError
+from objwrapper.exceptions import InvalidConfigError
 
 class S3Conf(object):
     def __init__(self, key_id, key, bucket_name, host, port, use_v4_sig, aws_region, use_https, path_style_request, sse_c_key):
+        if not host and not aws_region:
+            raise InvalidConfigError('aws_region and host are not configured')
         self.key_id = key_id
         self.key = key
         self.bucket_name = bucket_name
diff --git a/seafobj/objstore_factory.py b/seafobj/objstore_factory.py
index de70d78..75be544 100644
--- a/seafobj/objstore_factory.py
+++ b/seafobj/objstore_factory.py
@@ -60,8 +60,6 @@ def get_s3_conf(cfg, section):
     aws_region = None
     if cfg.has_option(section, 'aws_region'):
         aws_region = cfg.get(section, 'aws_region')
-    if not host and not aws_region:
-        raise InvalidConfigError('aws_region and host are not configured')
 
     use_https = False
     if cfg.has_option(section, 'use_https'):
@@ -106,8 +104,6 @@ def get_s3_conf_from_json(cfg):
     aws_region = None
     if 'aws_region' in cfg:
         aws_region = cfg['aws_region']
-    if not host and not aws_region:
-        raise InvalidConfigError('aws_region and host are not configured')
 
     use_https = False
     if 'use_https' in cfg:
@@ -134,18 +130,16 @@ def get_oss_conf(cfg, section):
     endpoint = ''
     if cfg.has_option(section, 'endpoint'):
         endpoint = cfg.get(section, 'endpoint')
-    if not endpoint:
+    region = ''
+    if cfg.has_option(section, 'region'):
         region = cfg.get(section, 'region')
-        endpoint = 'oss-cn-%s-internal.aliyuncs.com' % region
-
-    host = endpoint
 
     use_https = False
     if cfg.has_option(section, 'use_https'):
         use_https = cfg.getboolean(section, 'use_https')
 
     from objwrapper.alioss import OSSConf
-    conf = OSSConf(key_id, key, bucket, host, use_https)
+    conf = OSSConf(key_id, key, bucket, endpoint, region, use_https)
 
     return conf
 
@@ -158,11 +152,9 @@ def get_oss_conf_from_json(cfg):
 
     if 'endpoint' in cfg:
         endpoint = cfg['endpoint']
-    if not endpoint:
+    region = ''
+    if 'region' in cfg:
         region = cfg['region']
-        endpoint = 'oss-cn-%s-internal.aliyuncs.com' % region
-
-    host = endpoint
 
     use_https = False
     if 'use_https' in cfg:
@@ -170,7 +162,7 @@ def get_oss_conf_from_json(cfg):
             use_https = True
 
     from objwrapper.alioss import OSSConf
-    conf = OSSConf(key_id, key, bucket, host, use_https)
+    conf = OSSConf(key_id, key, bucket, endpoint, region, use_https)
 
     return conf
 
diff --git a/tests/utils.py b/tests/utils.py
index 7ee279d..b2173ad 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -23,6 +23,6 @@ def get_s3_client(sse_c_key):
 
 def get_oss_client():
     host = f'oss-{oss_region}.aliyuncs.com'
-    conf = OSSConf(oss_key_id, oss_key, oss_bucket, host, True)
+    conf = OSSConf(oss_key_id, oss_key, oss_bucket, host, oss_region, True)
     client = SeafOSSClient(conf)
     return client