Abstract: The presence of D-amino acid in proteins is thought to be a result of racemization of L-amino acid, which may influence the space structure and the functions of proteins and the connection to the occurence of some diseases has been demonstrated. Recently, tremendous advancement in instrumental techniques has brought the rapid development to analytical methods and detecting techniques in the research on racemization of protein amino acid. The advances in the relationship between racemization of protein amino acid and diseases, the influence factors on racemization of protein amino acid and the analytical techniques are reviewed in this article, and the research directions of racemization of protein amino acid are also given.