The nodes of wireless sensor networks have very limited energy

so improving energy efficiency is the first design goal for wireless sensor networks.An energy-efficient clustering algorithm is proposed.It proposes that candidates compete for cluster heads according to their residual energy within some coverage range in order to make the distribution of cluster heads balanced.The plain nodes between clusters choose their cluster head according to energy and distance to balance the load among the clusters.In data transmission phase

it builds a multi-hop routing tree among the cluster heads is built to send data to the base station reduce their communication load.The simulation results show that the new algorithm can reduce the energy consumption and prolong the network lifetime.