LEACH routing protocol for wireless sensor networks and a number of its improvements are proposed. Most of them use random selection of clusterhead node election. It is found that node’s energy consumption increases with its more random selection. Then performance of the network is affected because node’s energy consumed quickly. This paper proposed an improved routing algorithm that determines threshold of clusterhead node according to the node’s present remaining energy, distance to all surviving nodes and average distance between the node and convergence node. Routing is done by the threshold. Simulation shows that network performance and life cycle could be improve effectively.