Abstract: The sources and applications of the bioactive substance squalen that widely exists in animals and plants are reviewed.According to the citations,the most abundant sources of squalene in animals are deep-sea fishes,especially sharks,in which the highest content of squalene is approached to 69% based on liver oil.Amaranth seed oil,olive oil and palm oil are the major plant sources of squalene.The content of squalene is 5 %-8% in amaranth seed oil,and the highest content is 1.16% in olive oil.Because of the strong bioactivity,squalene is widely used in medical care fields and in cosmetics.Squalene is easy to oxidize,so it must be kept with suitable antioxidant during storage.