diff --git a/oss2/api.py b/oss2/api.py
index 8562bfdf..f639ce96 100644
--- a/oss2/api.py
+++ b/oss2/api.py
@@ -119,7 +119,6 @@ def progress_callback(bytes_consumed, total_bytes):
 from .models import *
 from .compat import urlquote, urlparse, to_unicode, to_string
 
-import time
 import shutil
 import oss2.utils
 
@@ -247,6 +246,8 @@ class Bucket(_Base):
     STATUS = 'status'
     VOD = 'vod'
     SYMLINK = 'symlink'
+    QOS = 'qos'
+
 
     def __init__(self, auth, endpoint, bucket_name,
                  is_cname=False,
@@ -828,6 +829,37 @@ def delete_bucket(self):
         resp = self.__do_bucket('DELETE')
         return RequestResult(resp)
 
+    def head_bucket(self):
+        """探测一个Bucket是否存在。
+
+        :return: :class:`HeadBucketResult <oss2.models.HeadBucketResult>`
+        """
+        resp = self.__do_bucket('HEAD')
+        return HeadBucketResult(resp)
+
+    def put_bucket_storage_capacity(self, num_giga_bytes):
+        """设置Bucket容量限额。
+
+        :param int num_giga_bytes: 容量限制，以GB为单位；-1表示没有容量限制。
+
+        :return: :class:`RequestResult <oss2.models.RequestResult>`
+        """
+        input = BucketQos(storage_capacity=num_giga_bytes)
+        data = self.__convert_data(BucketQos, xml_utils.to_bucket_qos, input)
+
+        resp = self.__do_bucket('PUT', data=data, params={Bucket.QOS: ''})
+        return RequestResult(resp)
+
+    def get_bucket_storage_capacity(self):
+        """获取Bucket容量限额。
+
+        :return: 返回当前Bucket容量限额，以GB为单位。如果没有限制则返回-1。
+        """
+        resp = self.__do_bucket('GET', params={Bucket.QOS: ''})
+        bucket_qos = self._parse_result(resp, xml_utils.parse_get_bucket_qos, GetBucketQosResult)
+
+        return bucket_qos.storage_capacity
+
     def put_bucket_acl(self, permission):
         """设置Bucket的ACL。
 
diff --git a/oss2/models.py b/oss2/models.py
index 3c617ac3..6c3229c2 100644
--- a/oss2/models.py
+++ b/oss2/models.py
@@ -310,6 +310,13 @@ def __init__(self, resp):
 BUCKET_ACL_PUBLIC_READ_WRITE = 'public-read-write'
 
 
+class HeadBucketResult(RequestResult):
+    def __init__(self, resp):
+        super(HeadBucketResult, self).__init__(resp)
+
+        self.location = _hget(self.headers, 'x-oss-bucket-region')
+
+
 class GetBucketAclResult(RequestResult):
     def __init__(self, resp):
         super(GetBucketAclResult, self).__init__(resp)
@@ -430,6 +437,22 @@ def __init__(self, resp):
         BucketLifecycle.__init__(self)
 
 
+class BucketQos(object):
+    """Bucket QoS设置。
+
+    :param int storage_capacity: 容量限额，单位为GB。
+    """
+    def __init__(self, storage_capacity=-1):
+        self.storage_capacity = storage_capacity
+
+
+class GetBucketQosResult(RequestResult):
+    def __init__(self, resp):
+        super(GetBucketQosResult, self).__init__(resp)
+
+        self.storage_capacity = -1
+
+
 class CorsRule(object):
     """CORS（跨域资源共享）规则。
 
@@ -701,6 +724,7 @@ def __init__(self, resp):
         RequestResult.__init__(self, resp)
         LiveChannelStat.__init__(self)
 
+
 class GetLiveChannelHistoryResult(RequestResult, LiveChannelHistory):
     def __init__(self, resp):
         RequestResult.__init__(self, resp)
diff --git a/oss2/xml_utils.py b/oss2/xml_utils.py
index 54b0f184..f12da252 100644
--- a/oss2/xml_utils.py
+++ b/oss2/xml_utils.py
@@ -386,6 +386,14 @@ def parse_get_bucket_cors(result, body):
     return result
 
 
+def parse_get_bucket_qos(result, body):
+    root = ElementTree.fromstring(body)
+
+    result.storage_capacity = _find_int(root, 'StorageCapacity')
+
+    return result
+
+
 def to_complete_upload_request(parts):
     root = ElementTree.Element('CompleteMultipartUpload')
     for p in parts:
@@ -479,6 +487,7 @@ def to_put_bucket_cors(bucket_cors):
 
     return _node_to_string(root)
 
+
 def to_create_live_channel(live_channel):
     root = ElementTree.Element('LiveChannelConfiguration')
 
@@ -492,3 +501,11 @@ def to_create_live_channel(live_channel):
     _add_text_child(target_node, 'PlaylistName', str(live_channel.target.playlist_name))
 
     return _node_to_string(root)
+
+
+def to_bucket_qos(bucket_qos):
+    root = ElementTree.Element('BucketUserQos')
+
+    _add_text_child(root, 'StorageCapacity', str(bucket_qos.storage_capacity))
+
+    return _node_to_string(root)
\ No newline at end of file
diff --git a/tests/test_bucket.py b/tests/test_bucket.py
index bf7c1410..cfe03ade 100644
--- a/tests/test_bucket.py
+++ b/tests/test_bucket.py
@@ -245,6 +245,29 @@ def test_xml_input_output(self):
             self.assertEqual(result.allow_empty_referer, True)
             self.assertEqual(result.referers[0], to_string(u'阿里云'))
 
+    def test_head_bucket_normal(self):
+        head_result = self.bucket.head_bucket()
+        get_result = self.bucket.get_bucket_location()
+
+        self.assertEqual(head_result.location, get_result.location)
+
+    def test_head_bucket_not_exist(self):
+        auth = oss2.Auth(OSS_ID, OSS_SECRET)
+        bucket = oss2.Bucket(auth, OSS_ENDPOINT, random_string(63).lower())
+
+        self.assertRaises(oss2.exceptions.NotFound, bucket.head_bucket)
+
+    def test_bucket_storage_capacity(self):
+        old_capacity = self.bucket.get_bucket_storage_capacity()
+
+        if old_capacity == -1:
+            new_capacity = 100
+        else:
+            new_capacity = old_capacity + 100
+
+        self.bucket.put_bucket_storage_capacity(new_capacity)
+        self.assertEqual(new_capacity, self.bucket.get_bucket_storage_capacity())
+
 
 if __name__ == '__main__':
     unittest.main()