Abstract: Monodisperse SiO₂ particles were prepared by Stöber method.SiO₂ colloidal crystal was synthesized by the vertical deposition method.The crystal forms and micromorphology were characterized by X-ray diffraction（XRD） and Scanning electron microscope（SEM）.The results show that the SiO₂ particles are monodisperse non-crystalline spheres with the particle size in 70~380nm.The particle size increases with the increment of NH₃ concentration.Increasing the spacing between two Substrates,the ordered colloidal crystal with close structure is obtained.With the same spacing,binary colloidal crystal is more difficult to obtain.