Abstract: The nano ZnO/poly(methyl methacrylate)(nano ZnO/PMMA) composites were prepared by a simple and environmental friendly method. The functions including UV resistance, transparency, photoluminescence and antibacterial properties of nano ZnO/PMMA were studied. The monomer, initiator, precursor and catalyst were dissolved in ethanol at 30℃. The system were heated to 80℃, the polymerization of poly(methyl methacrylate)(MMA) and the synthesis of ZnO were carried out simultaneously.The nano ZnO/PMMA composites were obtained after solvent evaporation.The nano ZnO/PMMA composites were characterized by XRD, FTIR, TEM and UV-Vis. The results show the successful preparation of nano ZnO/PMMA composites, nano ZnO/PMMA composites could absorb ultraviolet radiation of 200-400 nm and have high transparency in visible region. The characterization of photoluminescence shows that nano ZnO/PMMA is able to emit bright blue-green light under excitation of ultraviolet light. The antibacterial testing result showes that nano ZnO/PMMA composites have significant antibacterial effect on staphylococcus aureus, the antibacterial rate is more than 99%. nano ZnO/PMMA composites perform multifunctional properties and have potential applications in many areas, such as UV shielding coatings, UV resistant plexiglass, fluorescent materials, antibacterial plastic products, and so on.