Abstract: Monolithic mesoporous silica was prepared by a sol-gel technique. The ZnS/ SiO₂ assembly systems withdifferent ZnS loading (0. 05 , 0. 1 , 0. 2 and 0. 5 mol/ L) were obtained by immersing , followed by drying and thermalreaction. It was found that the optical absorption edges and the peaks of fluorescence spect rum have a red2shif t withincreasing the ZnS loading concent ration. The photoluminescence intensity of samples is enhanced along with theincrease of the annealing temperature and slows down for the samples annealed at temperature above 450 ℃. Thecalculated result shows that the size of ZnS particles in the mesoporous SiO₂ is similar to it s exciton radius in magnitude. The shif t of the absorption edge is att ributed to the quantum size effect .