An efficient geographical routing algorithm,called AOGR（Asymptotically Optimal Geographical Routing）,has been proposed for multimedia wireless sensor networks. The existing geographical routing protocols aim at optimizing the single packet routing performance,while the new algorithm reduces the average hops of all the packets in a session. In AOGR,the reference of the delivered packets to subsequent packets in the routing will be exploited. With the increase of the routed packets,AOGR converges to the shortest path asymptotically. The simulation results show that the proposed algorithm can mitigate inefficient detours on the routes obtained by GPSR (Greedy Perimeter Stateless Routing) in its perimeter mode and reduce the average hops.