Abstract: In this paper,studies were made of the operation parameters influencing the asperuloside yield, which was extracted from the leaves of Eucommia ulmoides by ultrasonic-assisted extraction. The main operation parameters, such as:the ethanol concentration, the liquid-solid ratio, the ultrasonic irradiation time and the ultrasonic irradiation power, were investigated in detail. And the highest yield of asperuloside was obtained in the condition of ultrasonic irradiation power of 160 W, 70% of ethanol concentration, 15 mL·g^-1 of liquid-solid ratio, and 40 min of ultrasonic irradiation time. As a conclusion, it was found that the ultrasonic-assisted extraction was a stable, efficient, and energy-saving technology, which could be used in the extraction of asperuloside from Eucommia ulmoides.