Citric-soluble collagen (CSC) and pepsin-soluble collagen (PSC) were successfully extracted from donkey skin, and the characterization of the collagens was investigated and compared. The results showed that both collagens exhibited a maximum absorbance at 234nm, but little absorbance near to 280nm. FTIR measurement of ASC and PSC were quite similar, and suggested the existence of triple-helix structure. Based on sodium dodecyl sulfate-polyacrylamide gel electrophoretic(SDS-PAGE) patterns, both samples were identified as type I collagen, containing two different α chains (α1 and α2). But thermal transition temperature of PSC (65.3℃) was slightly higher than the corresponding ASC (51℃) though the DSC(differential scanning calorimetry) detection. The hydroxyproline determination showed the purity of ASC was higher than that of PSC.