Abstract: In this study, the fresh Kyoho grapes were used as test materials, and the preservation effects of four chitosan（50, 150, 250, 500 kDa） with a concentration of 10 g/L and the mixture on grapes during shelf life were analyzed. Results showed that all treatments could be benefit to the grapes preservation in varying degrees on sensory index, soluble solid content, VC content, absorption strength, titratable acid content and anthocyanin content.Among them, the coating film treatment mixed by 4 kinds of high molecular weight chitosan with equal proportion presented the best penetration effects. Compared with the first day, the soluble solid contents of treatment groups was decreased by 19.7% to 31.6% on the ninth day of shelf life（control group of 38.2%）, and there was a highly significant difference（P＜0.01） between the mixture and other experimental groups. The decrease rates of respiration intensity were 58% to 85% in treatment groups（control group of 30%）, and there was a highly significant difference between highly significant difference（P＜0.01） between the mixture and other experimental groups. The decrease rates of VC contents in treatment groups were 38.5% to 65.5%（control group of 71.9%）, and there was a significant difference between（P＜0.05） between the mixture and control groups. Therefore, the coating film treatment mixed by 4 kinds of high molecular weight chitosan with equal proportion could effectively delay the senescence of grapes and decrease of grapes qualities, and the preservation effect on Kyoho grapes was better than that of individual chitosan coating film treatment.