Wireless sensor networks consist of small battery powered devices with limited energy resources. Once deployed, the small sensor nodes are usually inaccessible to the user and thus replacement of the energy source is not feasible. Hence, energy efficiency is a key design issue that needs to be enhanced in order to improve the life span of the network. The efficiency of sensor networks strongly depends on the routing protocol used. In this paper, the authors have compared the performances of two popular routing protocols: LEACH and PEGASIS by considering the chaining system in the total network.