Abstract: Ultrasonic-assisted method was used to extract the total flavonoids from Mentha haplocalyx, and the effects of ethanol concentration, ultrasonic treatment time, solid- liquid ratio and bath temperature on the extraction rate of total flavonoids were investigated. On the basis of single factor tests, the extraction technology of total flavonoids from Mentha haplocalyx was optimized by response surface methodology. The optimum conditions obtained were as follows:ethanol concentration was 50%, extraction time was 30 min, solid-liquid ratio was 1∶20 and bath temperature was 50℃. Under this conditions, the extraction rate values of total flavonoids was 3.11%±0.06%.