Abstract:CdS/SiO2 composites were prepared by gel confined - anion exchange method. Structures, physical properties and visible light photocatalytic hydrogen production properties of CdS/SiO2 composites were characterized by XRD, SEM, HRTEM, BET, UV-vis and GC. Properties of cadmium sulfide nanoparticles prepared by hydrothermal and precipitation method at room temperature were compared. The results show that CdS size prepared by silica gel confined is 3-7 nm, specific surface area of CdS/SiO2 is 68.99 m2/g, and absorption band edge red shifts to 605 nm. In absence of catalyst, photocatalytic hydrogen production rate of CdS/SiO2 is 1 925.29 μmol/(h?g), which is 47 and 2.3 times than those of hydrothermal and precipitation method room temperature, respectively, and photocatalytic cycle of CdS/SiO2 is more stable.