Abstract: Ultrasonic-assisted extraction was applied to extract chlorophyll from radish leaf. By means of Box-Behnken design with four factors (extraction temperature, ultrasonic power, liquid-solid ratio and extraction time) as influence factors, the optimal extraction technology was determined by the experiments. The results indicated that the yield of chlorophyll was affected obviously in decreasing order by liquid-solid ratio, extraction temperature, ultrasonic power and extraction time. The optimized ultrasonic-assisted extraction conditions of chlorophyll were obtained as follows: extraction temperature 73℃, ultrasonic power 175 W, liquid-solid ratio 13 mL/g, extraction time 46 min. Under the above mentioned conditions, the yield of chlorophyll from radish leaf was 0.413%. The experiment result was consistent with the prediction result. This research can provide a technical reference for chlorophyll extraction from radish leaf.