Abstract: Porous silicon (PS) was prepared by the double-cell electrochemistry corrosion, and undergone an ultrasonic post-treatment after etching.The Cu nanoparticles with the uniform size and regular shape were prepared by one step impregnation on the treated PS template.The effect of deposition time on shapes and sizes of nanoparticles was investigated.Results show that ultrasonic post-treatment does not destroy the physical and chemical structure of PS, plenty of SiHx species and honeycomb-like porous structure (about 150 nm) provide reduction and site of formation and growth of Cu nanoparticles, respectively.The deposition time plays a key role on the shape and size of Cu nano-particles, and Cu nano-particles with the uniform size and regular shape are obtained when the time was 40s.