Glycosylation is one of the most important post-translational modifications.The variety of galactosylation reactions significantly contributes to the tremendous diversity of oligosaccharide structures expressed by living organisms.α1,3 galactosyltransferase(GGTA1),ABO blood group antigens synthetase and isogloboside 3(iGb3)synthase catalyze the transfer of galactose via α1,3 linkages.Both ABO(for allo) and α-galactose(αGal)(for xeno)antigens expressed in the donor tissue produce a marked effect on immunological rejection of transplantation.In this review,the features of these enzymes,the antigens they synthesize and the function they perform during transplantation are discussed.