Nanocrystalline Cu x S (x=1, 2) thin films were deposited by asynchronous-pulse ultrasonic spray pyrolysis (APUSP) technique on glass from CuCl 2 and thiourea at relatively low temperature without any complexing agent. The deposited films chemically close to CuS were found to be polycrystalline phases, while the Cu 2 S films were a mixture of amorphous and polycrystalline as well. The crystalline phase of particles was highly depended on the molar ratio of thiourea to CuCl 2 and the pyrolysis temperature. The growth of Cu x S thin films was controlled successfully by the improved APUSP method. Characterization of the films has been carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. XRD and XPS analysis showed stoichiometric Cu x S (covellite CuS and chalcolite Cu 2 S). Raman shifts of the films were measured at 474 cm - 1 (CuS) and 472 cm - 1 (Cu 2 S).