Abstract: In this paper,the pepsin soluble type Ⅱ collagen(PSCⅡ)was extracted by pepsin from sturgeon(Acipenser sinensis)cartilage and its structure was characterized. The SDS-PAGE result showed that the PSCⅡ possessed two kinds of chains(α1 and β)and the molecular weight was about 110 and 200 ku,respectively. The maximum UV absorption of PSCⅡ was 229 nm and the fourier transform infrared(FTIR)and circular dichrosim(CD)results accorded with the characteristics of type Ⅱ collagen form other species. The amino acid analysis showed glycine was the highest population in PSCⅡ with the ratio of 1/3. Meanwhile,PSCⅡ was rich in alanine and proline. Differential scanning calorimeter(DSC)results showed the thermal denaturation temperature of PSCⅡ was 31.5 ℃. PSCⅡ could be used as a good drug carrier because of its porous structure under scanning electron microscope(SEM).