Abstract: An improved particle swarm optimization (IPSO) algorithm was proposed to solve reliability problems. The IPSO made use of three strategies to improve the velocity updating in PSO algorithm, thus benefiting the improvement of its develop ability to space solution. In addition, a dynamically adjusted inertia weight was introduced into the velocity updating so as to balance the global search and the local search of the IPSO algorithm. Experimental results showed that the IPSO algorithm has stronger convergence and stability than the other two PSO algorithms for solving reliability problems. So, IPSO is an efficient alternative for solving reliability problems.