Carbohydrates play important roles in a number of pathological processes such as cancer, infectious diseases, and inflammation. Detailed biophysical and biochemical studies of carbohydrates require sufficient quantities of defined oligosaccharides. Due to structure complexity, synthesis of complex carbohydrates with special linkages and configurations by traditional (non-biological) organic synthetic approaches continue to pose difficulties in spite of the significant advances in the field. Enzymatic synthesis by glycosyltransferases is considered an alternative solution. Chemoenzymatic synthesis combining the advantages of both organic synthesis and enzymatic synthesis is a method of choice to obtain complex carbohydrates and glycoconjugates.