A new ant-algorithm-based routing approach is propos ed for the VC routing problem with considering the comprehensive effect between the resource utilization and the load balance in ATM networks. In the approach, the backup paths are calculated first, an d then an ant algorithm based on the ability of ants to find the short est path between their nest and the food source during their searching food, is constructed to optimize the VC global route.Simulation results show that the proposed approach can realize VC routing effectively according to the current traffic states in the networks and the user-specified delay requirement s. A new ant-algorithm-based routing approach is propos ed for the VC routing problem with considering the comprehensive effect between the resource utilization and the load balance in ATM networks. In the approach, the backup path are calculated first, an d then an ant algorithm based on the ability of ants to find the short est path between their nest and the food source during their searching food, is constructed to optimize the VC global route.Simulation results show that the proposed approach can realize VC routing efficiently according to the current traffic states in the networks and the user-specified delay requirement s.