Based on multimedia broadcast/multicast service architecture(MBMS), this paper proposes an efficient QoS-based multicast approach for the Universal Mobile Telecommunications System (UMTS). Our approach adopts the existing scalable-coding technique to provide multiple levels of service quality to diverse mobile devices in the UMTS system. In this approach, two kinds of transmission modes are developed to utilize fully the network resources for wireline and wireless links. An analytic model is presented to investigate the performance of our approach and the 3GPP 23.246 approach. The numerical results indicate that in terms of transmission costs of core/radio networks, our approach outperforms the 3GPP 23.246 approach.