Polymethyl methacrylate cadmium was grafted on TiO2 surface via the surface initiated atomic transfer radical polymerization of methyl methacrylate cadmium from a surface tether initiator. The coordinated cadmium as the source precursor reacts with H2S generates CdS nanoscrystal on TiO2 surface. The grain size of CdS is about 5 nm and stabilized by tether polymer chains. The light absorption of CdS/TiO2 is expanded to visible light region.