Chinese yam， as a traditional plant of homologous medicine and food， has a long history of cultivation and consumption. Chinese yam is rich in nutrition， including polysaccharides， polyphenols， saponins and other active ingredients. It has a variety of physiological functions. This paper reviewed the main active components of Chinese yam and the mechanism of its nutritional function， such as regulating immunity， anti-inflammation， benefiting gastroenterology， regulating sugar and lipid metabolism， anti-oxidation etc.， and prospected its application prospect， so as to provide a theoretical basis for the study of Chinese yam.