Flaxseed is one of the top ten oil crops in the world,which is mainly used to produce oil in China.Flaxseed contains α-linolenic acid,lignans,flaxseed gum,flaxseed protein and other active components,thus giving it multiple biological activities such as antioxidant,anti-inflammatory,hypoglycemic,hypolipidemic,prevention of obesity and diabetes.This paper reviewed the nutritive and active ingredients in flaxseed.Besides,its effects of lipid-lowering and preventing obesity as well as their mechanisms were summarized,aiming to provide references for the research on the functions of flaxseed and development of its functional products.