Oat β-glucan is one of non-starch polysaccharides mainly found in the cell wall of oat endosperm and dextrin layer,and it is also a soluble dietary fiber,which is an important active component in oats.In this pa-per,the pathways and molecular mechanisms of oat β-glucan in weight loss,regulation of blood glucose and lipid levels,improvement of cardiovascular diseases,anti-tumor and regulation of immune function were reviewed to pro-vide references for disease prevention and treatment,as well as provide reference for the development and application of functional foods.