The crystal structure, surface morphology and preferred orientation of copper electro-deposit were investigated by using sulfate bath with SiO2 suspension and the cathode substrate Au-sputtered. By addition of colloidal silica in copper electrolytic bath and Au pre-coating on substrate, the grains of deposits became fined and uniform and the number of grains were increased. Hardness of copper eleetrodeposits with colloidal silica increased about 15% in comparison with that of pure copper deposit film. The (111), (200) and (311) planes in the X-ray diffraction patterns were almost swept away, so preferred orientation of copper deposits change from (111) to (110) plane by co-deposit SiO2 and pre-coating the substrate.