The paper deals with structural optimization for reducing vibration of engine pipeline.The method can give the best postion,stiffness and damping of clips to be attached on condition that pipe system's structure has been given.Based on the finit element analysis of original structure,the analytical process is limited between the locations where are to be attached clips,excited points and dangerous points.It is not necessary to make again a finit element analysis for the improved system.An exemple for reducing the vibration of an engine pipeline is presented.