Objective: To explore the biological effect of high frequency ultrasound and low frequency ultrasound on different layers in vitro swine adipose tissue. Methods: In vitro experiment was divided into two groups with working frequency of transducers being 6.5 MHz and 3 MHz. In 6.5 MHz group, ultrasonic power 2-5 W and irradiation time 5, 10, 20, 40, 60 and 80 s were adopted and cell activity was determined through MTT staining method and thus the area of coagulation necrosis was calculated. In 3 MHz group, biological effect induced by focused ultrasound on different layers of the swine adipose tissue was observed and the difference in result was discussed under same experiment parameters. Results:Lipolysis effect changes in an order with increasing ultrasonic power and irradiation time. 5 s irradiation time shows no obvious damage to the tissue, however shows obvious damage above 10 s. Under the same experiment parameters, deep adipose tissue (DAT) shows higher level of tissue damage than superficial adipose tissue(SAT). Only 3 MHz frequency can pass through the skin of thickness 5 mm at irradiation time≥40 s. Conclusion:Both high and low frequency ultrasound can effectively destroy adipose tissue.