Abstract: The ultrasonic cavitation and the response surface methodology were used to optimize the extraction process of the yellow pigment from flavedo of grapefruit, and a mathematical model of extraction time, solid- liquid ratio and ethanol concentration on the extraction of yellow pigment was established to obtain the optimal extraction process.The results showed that the effects of solid- liquid ratio and ethanol concentration on the absorbance of yellow pigment extract solution were significant, and the optimal extraction process was extraction time of 30 min, solid- liquid ratio of 1 ∶ 33 g / m L and ethanol concentration of 51%, under which the absorbance of yellow pigment extract solution was 1.778 ( n = 3) and there was no significant difference between prediction value.