Abstract: A load-balanced residual energy level based clustering routing protocol named RELCRP was proposed.In the stage of cluster formation, it was introduced that a priority based cluster head selection strategy in which node with higher priority was supposed to broadcast cluster head election notice much earlier, while accordingly node with low residual energy was averted to become a cluster head.In inter-cluster communication, a hybrid transmission mode of single-multi-hop was adopted.The cluster head switched transmission mode according to residual energy level so as to alleviate the "hot pot" problem induced by multi-hop transmission.Simulation results indicated that RELCRP efficiently balanced the energy consumptions of all nodes and eventually extended network lifetime.