In this paper, we propose a location-aware multicast protocol on MANET called MgCast (multiCAST for Multiple Geographical regions). Given a source node and a set of geographical destination regions, MgCast constructs and maintains a routing tree from the source to nodes which reside in the regions, in a decentralized manner. Our aim is to pursue trade-off between the route discovery ratio, the number of route request messages and the number of links of the tree. The experimental results have shown that MgCast could achieve a good balance between these metrics.