A facile region-selective deposition process was adopted to prepare high-dispersed CdS QDs on BiOCl nanosheets with the surface modification of thioglycollic acid (TGA). The samples were systematically characterized by XRD, SEM, TEM, HRTEM, EDS, XPS, UV-vis DRS, EIS and PL. The results indicate that CdS QDs with size of 5-10 nm dispersed uniformly on the surface of cuboid BiOCl nanosheets. The photocatalytic performance tests reveal that the CdS QDs-3%/BiOCl composite exhibits an excellent photocatalytic activity, which is over 4.0 and 4.8 times as high as pure BiOCl for methyl orange (MO) and phenol photodegradation rate under simulated solar light and UV light illumination, respectively. The enhanced photocatalytic performance of the CdS QDs/BiOCl composites should be attributed to the improved visible light absorption and the high migration efficiency of the photogenerated electron-holes due to the matched band gap and the widespread heterostructure between CdS QDs and BiOCl.