Abstract: Viburnum cylindricum oil was extracted by ultrasound assisted extraction. The influence factors of ultrasonic power, temperature and time on yield were studied, and the oil was analyzed by GC and FTIR. Resutls demonstrated that the optimum extraction conditions were as follows, using n-hexane as solvent, ultrasonic power was 100 W, the temperature was 50 ℃, and the time was 70 min, yield of oil was up to 25.86%, the oil mainly contained palmitic acid (24.63%), stearic acid (1.93%), oleic acid (39.61%), linoleic acid (28.93%), and linolenic acid (1.69%), and the content of unsaturated fatty acids was 70.23%. FTIR confirmed the ester group and double bond were in the structure of oil.