In this paper, we propose an improved PSO algorithm for solving constrained multiobjective optimization problems (CMOP). The new algorithm is based on the ε tolerable constrained Pareto dominance and and effective nondominated solution set maintenance strategy. To improve the convergence and diversity of the Pareto-optimal set, the position and velocity adjustment strategy and the Pareto-optimal solution searching (gbest) method are presented in this paper. The simulation results of the typical mutiobjective optimization problems demonstrate the validity of the algorithm.