OBJECTIVE：To opt imize the extraction technology of phenolic acid from Amomum tsaoko . METHODS ：The extraction technology of phenolic acid from A. tsaoko was optimized by using Box-Behnken design-response surface methodology with ethanol volume fraction ，liquid-solid ratio and extraction time as factors ，using the total contents of protocatechuic acid and vanillic acid as response value. The optimizd extraction technology was vlidated. RESULTS ：The optimal extraction technology was as follows ：ethanol volume fraction 65％，liquid-solid ratio 4∶1（mL/g），extraction time 2.5 h. After 3 times of validation tests ， average total content of protocatechuic acid and vanillic acid were 12.32 mg/g（RSD＝0.26 ％，n＝3），average relative error of which with predicted value （12.63 mg/g）was 2.45％. CONCLUSIONS ：The optimal technology is stable and feasible .