In this paper, we propose a location-based algorithm for supporting multicast routing in mobile ad-hoc networks. Instead of having routing paths in advanced to forward data packets from source node to multicast receivers, this algorithm let each node which receives data packets independently, adaptively determines the routing paths to forward data packets based on the information of its neighbor nodes. Before forwarding data packets, mobile node checks and uses one of its neighbor nodes as the next hop. Therefore, the availability of routing segments is ensured, providing high performance even in high mobility environment. The performance of this algorithm for multicast routing is validated via simulation using OPNET.