In this paper, we propose a new cache management scheme in the proxy server for location based services. The proxy server is able to cache query results of location-based services (LBS). One of the major LBS is mobile advertising. Mobile advertising is to distribute advertising messages to the target users with mobile devices. Nowadays, users are willing to receive mobile advertising messages. Users can issue queries to search advertisements within specific area. The searching area of the user query is seen as a rectangle in this paper. In traditional cache management, even though the searing areas of different users' queries are similar geographically, users' queries are still viewed as two different queries. The cache performance is low. In this paper, we propose the concept of the geographically partial matching for LBS. In geographically partial matching, two different queries are viewed as the same query if their searching areas are similar. As a result, the hit rate in the cache of the proxy server for LBS can be improved. The simulation results show that the partial matching can increase the re-utilization ratio of the cached content dramatically.