diff --git a/README.md b/README.md
index 045da47..4f4d935 100644
--- a/README.md
+++ b/README.md
@@ -15,10 +15,12 @@ IPIP.net officially supported IP database ipdb format parsing library
   <pre><code>
 import ipdb
 
-db = ipdb.Reader("/path/to/mydatatest.ipdb")
-print(db.find("2001:250:200::"))
-print(db.find_map("2001:250:200::"))
-
-info = db.find_info("2a06:e881:3800::")
-print(info.country_name, info.region_name, info.city_name, info.owner_domain, info.isp_domain, info.latitude, info.longitude, info.timezone, info.utc_offset)
+db = ipdb.City("/path/to/city.ipv4.ipdb")
+print(db.is_ipv4(), db.is_ipv6())
+print(db.languages()) // support language
+print(db.fields()) // support fields
+print(db.build_time()) // build database time
+print(db.find("1.1.1.1", "CN")) // query ip return array
+print(db.find_map("8.8.8.8", "CN")) // query ip return dict
+print(db.find_info("118.28.1.1", "CN").country_name)
   </pre></code>