The application of ultrasonic irradiation to extract pepsin-soluble collagen from the skins of rabbit was investigated in this study. The results showed that the extraction rate of collagen using the ultrasonic irradiation was (83.69±0.51) % and the yield increased by 25% in comparison with the conventional pepsin isolation method. The result of polyacrylamide gel electrophoresis confirmed that the subunits structure of collagen using the ultrasonic irradiation was mainly of α1, α2 and β, without subunit degradation. Moreover, the ultraviolet spectrum exhibited a typical absorption peak at 217 nm, indicating that it greatly maintained the characteristics of type I collagen. Additionally, the Fourier transform infrared spectroscopy revealed that hydrogen bond was partially destroyed, but the triple helix structure of collagen remained intact even after the ultrasonic irradiation. However, the result of Scanning Differential Calorimeter analyses showed that the thermal denaturation temperature and enthalpy value of collagen using the ultrasonic irradiation were slightly lower than that of the traditional rabbit collagen, and it still had a relatively higher thermal stability.