In this paper, we propose a Multicast Routing Protocol termed ZBMRP (Zone Based Multicast Routing Protocol) for Mobile Ad Hoc Networks (MANETs). ZBMRP applies on-demand procedures to dynamically establish mesh-based multicast routing zones along the path from the multicast source node to the multicast receivers. Control packet flooding is employed inside multicast zones, thus multicast overhead is vastly reduced, and good scalability can be achieved. It will also be easier to secure multicast routing. ZBMRP fits well for MANETs where bandwidth is limited, topology changes frequently, power is constrained and security problem is serious. Simulation results are presented to support our claim.