ZnS and ZnxCd1-xS nanocomposites were prepared in poly(methyl methacrylate) matrixes. By control of the amount of monomers in copolymerization, different Zn/Cd ratio samples were obtained. The solutions and films of these samples were characterized by absorption, fluorescence, and time-resolved spectroscopy. Continuous variation of the luminescence wavelength was observed by adjusting the molar ratio of Zn/Cd. The photophysical properties of these samples are discussed.