CdxZn1-xS thin films were prepared by chemical bath deposition in a solution containing cadmium chloride, zinc chloride, thiourea, sodium citrate and ammonia. The morphological, structural and optical properties of CdxZn1-xS films were investigated by X-ray diffraction, scanning electron microscopy, energy disperse spectroscopy and UV-vis-NIR spectroscopy. The photo-current response curves were also tested to study their electrical property. It was found that CdxZn1-xS thin films were successfully prepared at pH values from 10 to 13. With increasing of pH value, the ratio of zinc atom in the film and optical band gap decreased. All the films showed obvious photoconductive phenomenon. The CdxZn1-xS films prepared at pH=11 and 12 showed uniform and dense surface morphology and presented good crystallinity. Their optical band gaps were about 2.92eV and 2.72 eV respectively, with light and dark conductivity ratio of 1.20 both. The photo-currents in the samples fell more quickly when the light was turned off, with current reduction of about 68.55% and 69.39% after 10s.