Abstract: Collagen polypeptide was added in the polymerization process of acrylic acid to change the component of the resulting polymer as retanning agents in leather industry, and the application value was explored. The alkali-extracted collagen polypeptide was firstly crosslinked by glutaraldehyde, and then copolymerized with acrylic monomers obtain the copolymers. The copolymer was used to retan chrome tanned leather, and the retanned leather was characterized and compared. Results showed that the difference was observed in the grain surface appearance, thickening rate, strength and dyeing effect of the retanned leather. The conclusion is that the crosslinking with glutaraldehyde has a new retanning and filling function.