In this paper, based on ant-algorithm, we propose a QoS multicast routing scheme in Internet. We first describe ant-algorithm model and give ant-network model, then present an approach using ant-algorithm to optimize the multicast routes with QoS constaints. Finally, simulations has been made to show the efficiency of the approach in the environment of OPNET simulation software, and the simulation results show that the proposed approach can find the best optimal multicast routes which can satisfy the delay-bounded requirement and avoid congested nodes as soon as possible.