Wireless sensor networks can provide low cost solution accompanied with limited storage, computational capability and power for verity of real-world problems and become essential factor when sensor nodes are arbitrarily deployed in a hostile environment. The cluster head selection technique is also one of the good approaches to reduce energy consumption in wireless sensor networks. The lifetime of wireless sensor networks is extended by using the uniform cluster head selection and balancing the network loading among the clusters. We have reviewed various energy efficient schemes apply in WSNs of which we concentrated on selection of cluster head approach and proposed an new method called Sleep Scheduling Routing with in clusters for Energy Efficient [SSREE]in which some nodes in clusters are usually put to sleep to conserve energy, and this helps to prolong the network lifetime. EASSR selects a node as a cluster head if its residual energy is more than system average energy and have less energy consumption rate in previous round. Then, an Performance analysis and compared statistic results of SSREE shows of the significant improvement over existing protocol LEACH, SEP and M-GEAR protocol in terms of lifetime of network and data units gathered at BS.