The collagen in Amur sturgeon skin was isolated using sodium chloride (SSC, 4.55%), acetic acid (ASC, 37.42%) and pepsin (PSC, 52.80%), respectively. The collagens appeared to be dense sheet-like film linked by random-coiled filaments under SEM. The denaturation and melting temperature were 32.15 °C and 116.62 °C for SSC, 32.78 °C and 120.66 °C for ASC, 32.46 °C and 115.42 °C for PSC, assessed by CD and DSC. SDS-PAGE showed that the collagens were mainly type I with two different α chains. The amino acid profiles of them was similar to each other with high imino acid content and hydroxylation degree. FTIR confirmed the triple helical structure of the collagens, and indicated more hydrogen bond in PSC and more intermolecular crosslinks in ASC. These results suggested that the collagens have potential in commercial applications as alternatives to mammalian collagen. Display omitted