In wireless sensor networks, sensor node always have a limited power resource. The energy consumed by sensor nodes to transfer the data to its destination becomes critical issue in designing WSN routing protocols. In this paper we propose a cluster routing protocol named I-LEACH to enhance the routing protocol LEACH. In the I-LEACH algorithm, selection of cluster heads is modified by using power of the sensor nodes in order to balance the network loads. The simulation results shows that I-LEACH performs 55% better than LEACH algorithm in terms of network lifetime