Abstract: This paper studies the bandwidth，delay and other QoS routing problems，presents a modified　population migration algorithm for QoS routing to optimize network resource utilization，which selects the resource consumption and load distribution as objective functions.The algorithm avoids the limitations of the old PMA such as local convergence，too computationally intensity and a long computational time.The purpose is to balance load，make good use of network resource，and reduce network congestion.Simulation results show this algorithm is stable and effective.

Key words: modified population migration algorithm, QoS routing, optimization

摘要： 研究了带宽、时延等QoS路由问题，针对原人口迁移算法易收敛于局部最优且计算量大，计算时间长的特点，提出了一种改进的人口迁移算法（modified Population Migration Algorithm），并将其应用于QoS路由选择优化问题。算法采用网络资源消耗和负载分布为目标函数，目的是在消耗网络资源最小的基础上，使负载均衡分布，合理利用网络资源，降低网络拥塞。仿真结果表明，该算法是有效的、稳定的。

关键词: 改进的人口迁移算法, QoS路由选择, 优化