Abstract: To improve the quality of Agaricus bisporus under refrigerated conditions, poly lactic acid, nanometer TiO₂ and silver nanoparticles were used to prepare antibacterial composite films, and the physicochemical properties including weight loss rate, firmness, VCcontent, reducing sugar content, total number of colonies and the changes of respiration intensity, were further studied.The results revealed that nanometer TiO₂ and silver nanoparticles possessed certain inhibitory effects on the number of microbial growth of Agaricus bisporus, respiratory intensity, reducing sugar content and the decrease of V_C content, among which, the antibacterial film with 3% nanometer TiO₂, was shown to be the best of keeping the quality of Agaricus bisporus in16 day.