Résumé : Traditional IP Multicast has been proposed in order to manage group communications over the Internet in a bandwidth efficient manner. Although this proposition has been well studied during the last decade there are still some problems for its deployment. In this paper, we propose a new algorithm mQMA that deals with two important problems of traditional IP multicast, i.e., multicast forwarding state scalability and Quality of Service routing. The algorithm mQMA deals with these two main problems while utilizing the technique of multicast aggregation in case of multi-constrained QoS. With this technique of aggregation several groups can share the same tree respecting the same QoS requirements. The algorithm mQMA builds trees satisfying multiple QoS constraints. We show, during the simulations, that mQMA reaches the same QoS performances as Mamcra which is the main multi-constrained multicast routing algorithm. Moreover, mQMA reduces dramatically the number of trees to be maintained and the number of multicast forwarding states.