Abstract:Collagen is a kind of biological macromolecule，and it is the most abundant and widely distributed functional protein in mammals.In the recent years，due to various limitations of terrestrial mammals，the isolated collagen from aquatic has gradually served as an alternative source of collagens.The aquatic collagen has many physiological functions；especially its improvements on photoaging skins attract many attentions by researchers from home and abroad.The current knowledge of collagen was briefly introduced in this paper，including the extraction methods of collagen and the improvements of aquatic collagen on photoaging skin.The objective was to help to provide a solid theoretical basis for further research on the development and utilization of collagen.