Abstract: The optimal extraction conditions and anti-tumor activities of polyphenols from the fruit of Diospyros kaki Thunb. were studied in this article. The optimal polyphenols extraction conditions were acquired based on the single factor experiment,binary multiple regression fitting and Box-Behnken multimodel experiment,and optimized by response surface methodology. The optimum conditions for polyphenols extraction from persimmon were as follows:extraction time 2.9 h,temperature 70℃,ethanol concentration 75%. Under the optimum conditions,the extraction ratio of polyphenols was 3.184 mg/100 g. Based on the result of MTT,it is found that persimmon polyphenols has an inhibitory effect on CL1-5 cells with the IC₅₀ value of 73.8 μg/mL,and the result showed polyphenols have an inhibitory effect on human lung cancer cell line CL1-5.