Astaxanthin belongs to lutein in carotenoids and is a secondary metabolite synthesized by many microalgae, yeasts and bacteria. Astaxanthin has been listed as one of the best preventive and therapeutic agent for many acute or chronic diseases due to its unique chemical structure.Based on current research trends, the existing data on astaxanthin in various biological activities, including antioxidants, regulation of inflammation and atherosclerosis, skin damage, neurodegeneration, tumor and immune activity, improved cognitive function and repair of damaged DNA, were summarized in order to provide theoretical guidance for the functional study of astaxanthin.