Abstract: Due to heterogeneity in the power of nodes, asymmetric link is commonly encountered phenomena in wireless sensor networks (WSN). Most of the routing protocols in WSN are proposed to work on bidirectional links which render the use of asymmetric links infeasible. In this study, we propose LEERP: A layer based energy efficient routing protocol for wireless heterogeneous sensor networks (WHSN) that makes use of asymmetric link to provide better energy efficiency and higher delivery rate. The LEERP protocol first identifies the asymmetric link and provides bidirectional for those links by reverse path algorithm. Then, it uses level values and energy threshold value to select next forwarding nodes in the neighbor list of each node. Simulation results show that our protocol significantly outperforms the other existing methods in WHSN.