Pd films are deposited on the Si wafers by the reduction of palladium(Ⅱ) hexafluoroacetylacetonate, which is used as the precursor, in the supercritical CO2 solution at temperature 100 ℃ and pressures between 12 and 18 MPa, and with reaction for 1020 h. The films are continuous, uniform and 0.31.5 m thick. The analyses of the Pd films by X-ray photoelectron spectroscopy and X-ray diffraction indicate that the structures of the deposited films are of single matter and nanocrystalline. The scanning electron microscope images show that pressure is a factor of affecting the size of the grain of the deposited film. At a pressure of 12 MPa, the size of grain is between 30 and 60 nm, at a pressure of 15 MPa, it is between 90 and 120 nm. Moreover, at a pressure of 18 MPa, it is between 150 and 180 nm. At the same temperature, with higher pressures, the size of the grain is bigger. On the same conditions, Pd thin films are deposited on the inner and the outer surfaces of cylindrical cavity.