Abstract: By separating and appraising pathogen during storage of snap beans the decay factors of snap beans were discussedand the antimicrobial agent was determined in this paper. The effects of different chitosan preservatives coating on thestorability of snap beans were determined. The results showed that the pathogens were Xanthomonas campestris and Botrytiscinerea. Sodium Dehydroacetate was the most effective antimicrobial agent. The optimum proportion of the preservative wasrespectively as follows: Chitosan quantity 2.0%,Sodium Dehydroaceate 0.2×10-6 and 6-BA 30×10-6.

Key words: snap bean(Phaseolus vulgaris L.), chitosan, coating storage