Abstract: ODMRP protocol is an on-demand multicast routing protocol in Ad hoc network.This paper presents the On-Demand Multicast Routing Protocol（ODMRP） with On-Demand Clustering.SC-ODMRP introduces source based clustering technique to reduce the flooding control overhead and improves the performance of networks.At the same time，SC-ODMRP reserves other key merits of ODMRP such as high performance in conditions with frequently changing topology.Analysis and simulation show that the protocol is characterized with its quick convergence and low maintenance costs of routing，robust and efficient flooding platform over dense，large mobile networks.