Abstract: The absorbance of yellow pigment was used as the measurement indicator. The regression equation was established by using four factorsthree levels experimental model of BoxBehnken central composite on the basis of single factor test. The extraction method of yellow pigment from Forsythia suspensa Vahl. was optimized by response surface methodology. The results showed that optimal extraction conditions were as follows: solidliquid ratio of 1∶28， alcohol concentration of 96%， ultrasonic time of 31 min， ultrasonic temperature of 72℃. The practical value was 07355， which was close to the model prediction extraction absorbance of 07557.

Key words: Forsythia suspensa Vahl., yellow pigment, response surface methodology (RSM), ultrasonic extraction