Abstract: Objective: The persimmon deastringency process was optimized by using salt,alum solution soaking persimmon fruit.Methods: The effects of the mass ratio of salt and alum,astringent temperature,astringent time on the soluble tannin content and hardness of the persimmon were investigated by Box- behnken using design methods.Results: The order of the influence of the three factors on the soluble tannin content and hardness was alum mass ratio > astringent temperature > astringent time,and the optimized conditions was salt,alum mass ratio of 3∶ 1,astringent temperature was 33.7 ℃,astringent time of 24 h.According to model predictions,soluble tannin content was reduced to 0.1430%,the hardness was 0.3719 MPa.Conclusion: The study showed that the persimmon deastringency process was optimized,deastringency efficiency was improved,which was accurate and reliable,suitable for processing astringent persimmon.