An Mobile Ad hoc network (MANET), a temporally formed network, consists of a collection of mobile nodes with wireless interfaces. The communications among nodes within an MANET are performed through wireless interfaces and usually are multi-hops. The topology of an MANET is changing. As there is no pre-established infrastructure within an MANET, nodes move freely and can easily form a network. Therefore, MANETs are widely used in military and civil areas.Multicast is a way of communications between one point to multiple points or multiple points to multiple points. QoS (Quality of Services) is a set of pre-defined service requirements for network users. Routing, a most popular research area in MANETS, aims at route discovery, route selection and route maintenance.The applications of MANETs in multimedia services, video telephone, and more require that the multicating routing in MANETs to support QoS, which is challenging.After introducing and analyzing some well-known multicast routing protocols, QoS routing protocols, and ODMRP (On Demand Multicasting Routing Protocol), this study focuses on improving the ODMRP to support QoS multicasting which leads to an extended ODMRP protocol, referred to as QODMRP. In the QODMRP, suitable multicasting routes satisfying requirements are selected by introducing thresholds of delay and bandwidth. Simulation shows that the QODMRP, which supports QoS, outperforms the ODMRP in packet delivery rate and so on. This study is useful for MANET to be applied in a various areas including multimedia communications.