Abstract: Not only does protein glycosylation exist in organisms in nature, but also is a promising method to improve activities of proteins. Previous studies indicated that glycosylation between proteins and sugars could significantly improve functional characteristics of proteins and was superior to other modification methods. The mechanisms of glycosylation reaction, synthetic approaches, evaluation methods as well as enhanced effects of glycosylation on solubility, emulsification, thermal stability, antioxidant activity, and antimicrobial property were systematically represented, together with effects of glycation of protein structure. And the protein glycosylation research directions in the future were also proposed.