Polystyrene (PS) photonic colloid crystals were assembled from PS spheres prepared by emulsion-free polymerization through an improved vertical deposition method that could shorten the assembly time efficiently. The monodispersity of the spheres was appraised according to the standard deviation. The results showed that the PS spheres had a high monodispersity with a standard deviation of 3.7% and a dispersion coefficient of 0.02. The morphology and bandgap structure were observed with scanning electron microscopy images and transmission spectra, respectively. The mechanism of vertical deposition was analyzed simply. As an application of PS colloid crystals, ordered macroporous TiO2 photonic crystals were prepared, and the structure and properties of macroporous TiO2 were also studied with various analytical methods, which provided some values for the fabrication of photonic crystals with a complete bandgap. (C) 2007 Wiley Periodicals, Inc.