Abstract: Route cache strategy is important in an on demand routing protocol in wireless mobile ad hoc networks. In on demand routing protocol the route discovery mechanism is used to transmit packets from one mobile node to other. In order to avoid such route discovery mechanism each time when the packet is transmitted, the route caching technique is used. Route caching is the major approach to decrease the flooding of the network by avoiding the route discovery operation as much as possible. Because the frequently use of route discovery mechanism is very costly in terms of delay and bandwidth consumption which can cause congestion and long delay. Therefore the efficient caching strategies have the great impact on the performance of the DSR and AODV routing protocol. This paper, presented the effect of the cache expiry time and active route timeout (ART) on the performance of the DSR and AODV routing protocols in terms of route discovery time, routing traffic overhead and throughput. The simulation results indicate that the performance of the DSR and AODV protocol decreases if we increase the cache size and ART parameters.