Abstract: Many routing algorithms were proposed for mobile ad hoc network (MANET). They can be classified into two categories: connection-oriented and connectionless. Their performance is usually limited under high mobility or various node densities. A connectionless algorithm even encounter a local maximum problem (also called void problem) under low node density. The problem causes a data packet cannot be transmitted to the destination Mobile Node (MN). Therefore, an improved OHLAR (one-hop location-aided routing) algorithm is proposed in this research. It is designed for the hybrid environment consisting of MANET and WiMAX networks. WiMAX network is used to overcome the broadcast storm of location interchange among MNs under high mobility or high node density. It can also resolve the local maximum problem under small or low node density. Simulation results show that the improved OHLAR can keep high delivery ratio, low end-to-end delay and low control overhead compared to the basic OHLAR and other routing algorithms, including AODV, LAR and CAM.