Recently, many researchers have become interested in Mobile Ad hoc Networks (MANET) to construct a selfconfigurable network without existing communication infrastructure. In this paper we focus on the performance of on-demand routing protocols such as DSR, AODV, and TORA in MANET. We have observed the performance change of each protocol through simulations with varying the application data such as sensor, text, voice, and video data. And then, we have evaluated the performance of three protocols in a predesigned ad hoc network, which has 20 mobile nodes. We have also assumed the link layer as the IEEE 802.11 wireless LAN. We have analyzed the simulation results with respect to packet delivery fraction, average end-toend delay, routing load for application data. Then, we present the possible alternative to routing protocols and wireless characteristics for the types of application data. Moreover, we believe that research result can be helpful to the community with similar interest.