The α-solanine was separated from the potato peel.The antimicrobial activities of α-solanine against Botrytis cinerea in vitro were studied with oxford cup method,and the minimum inhibitory concentration(MIC) was determined with the spread plate method.The results showed that,α-solanine had good antimicrobial effects on Botrytis cinerea,and a pronounced concentration dependency.When the concentration of α-solanine was 50 μmol/L,Botrytis cinerea showed high sensitivity.The MIC of α-solanine against Botrytis cinerea was 15%.With Botrytis cinerea as the indicator for the stability study,α-solanine showed the strongest antimicrobial effects on against Botrytis cinerea in the neutral condition(pH=7).When the heating temperature was lower than 80 ℃,the antimicrobial activities of α-solanine was relatively stable,and when the temperature was up to 121 ℃,the antimicrobial activities decreased following with the increasing of heating time.