Nanocrystalline TiO2 was prepared by the sol-gel method, and raw gelatin and its modified samples crosslinked with formaldehyde acted as dispersers in this method. Transmission electron microscope and X-ray diffractometer measurements showed, using modified gelatin samples, the prepared TiO2 nanocrystals have smaller particle size and more homogeneous particle distribution at the same calcining temperature. Following Fourier transform IR spectroscope analysis, the dispersion mechanism is considered to be through the bonding of TiO(NO3)(2) . H2O with the peptide chains of gelatin by a hydrogen bond.