Abstract: A new QoS(quality of service) multicast routing problem based on ant colony algorithm is presented.The route selection strategy and the control parameters of the ant colony are adjusted adaptively in different iteration steps.It makes comprehensive consideration of all the constraints of QoS routing problem,and takes into account the individual characteristics of each constraint.Experimental results show that this algorithm has a higher fitness to the constraints and gets much more diversified solutions and higher convergence speed;it can meet the service quality requirement in real network.