Abstract:Sialic acid is a kind of acidic sugar with nine carbon skeletons，which has important physiological significance in embryo and central nervous system development，cell recognition，adhesion，differentiation，signal transduction and other aspects.N-glycoloylneuraminic acid（Neu5Gc）is an acidic amino sugar with nine carbon atoms and a pyranose structure. As a special existence of sialic acid，Neu5Gc is closely related to the occurrence and development of human cancer，atherosclerosis，type 2 diabetes and other diseases. This paper mainly expounded the basic structure of Neu5Gc and the process of origin，metabolism，absorption and accumulation in human body，and introduces the theory of red meat specific pathogenesis and hazards of Neu5Gc.