Abstract: Monodisperse polystyrene (PS) colloidal particles were prepared by a quick emulsifier-free emulsion polymerization (EFEP) method, and their highly ordered colloidal crystals were fabricated by both centrifugal method and vertical surface method. Scanning Electron Microscope (SEM) and VIS-UV were used to study the topography, structure and optical properties of the colloidal crystals. The resulting planar samples by centrifugal method were distinctly thicker than that by vertical surface method. PS colloidal crystals by centrifugal method with a velocity of 1 000 r/min and a temperature of 40 ℃ exhibited a highly ordered three-dimensional structure. The optimized assembly conditions were discussed via samples’ optical properties and the transmission spectra showed the peak wavelength suffered a shift with the change of the PS spheres’ diameter.