Using pheromone of ant coloney system as reference, a novel method of solving TSP problem is proposed. That is using particle swarm optimization ( PSO) . PSO is used because of its simple operation, easy implementation and faster speed. In order to improve the popularity of the particle swarm,make the particle swam not to homogeneous too fast and decrease the possibility of local constrain, the algorithm decides the number of degenerated particles based on a designated popularity function.Experiment results and comparison studies have demonstrated that our work is useful.