A preliminary study has been made on the reactivities of dimethylgold(III)beta-diketone with a solid surface using two types of TiO2 powder, anatase and amorphous, in order to develop a novel gas-phase method for the preparation of highly dispersed gold catalysts. The organogold compound was adsorbed at 33 degrees C on the surface of TiO2 that had been pretreated under a variety of conditions and was decomposed into metallic gold particles by calcination in air at different temperatures. The despersion of gold particles and the catalytic activity of Au/TiO2 samples for CO oxidation were as high as those obtained by the liquid-phase deposition-precipitation method. Moreover, the chemical vapor deposition method was found to be potentially more advantageous in depositing gold particles that are smaller than 2 nm in diameter.