Standard particle swarm optimization presented in 2007(namely

PSO-2007)inclines towards stagnation phenomena in the later stage of evolution

which leads to premature convergence.Therefore

a PSO based on dynamic boundary(namely

DBPSO)is proposed in this paper.According to the movement characteristics of particles at stagnation stage

DBPSO introduces a strategy of boundary adjusting in PSO-2007.By tracking the distribution of the particles’locations

DBPSO adjusts the boundary of search space dynamically

which could guide the particles to more promising region.This strategy helps PSO-2007 decrease premature convergence and improve convergence precision.The results of experiments of four typical functions show that DBPSO are feasible and effective.