Abstract: The distribution of nodes in wireless sensor network(WSN) is random and equal clustering algorithm arouses energy consumption unbalance.So this paper presented an energy-balanced unequal clustering algorithm(EBUCA)．Based on residual energy and density,it selects cluster heads,then forms different size of cluster by density of the cluster heads and the distance to sink ,making the clusters with higher density and closer to the base station to have smaller size to achieve the purposes of balancing energy and loads．The simulation results show that compared with LEACH,DBCP,EEUC,the improved algorithm can balance the energy consumption of nodes,and prolong the life-time of the network.

Key words: Wireless sensor network,Density,Energy-balanced,Unequal clustering,Network lifetime