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 structurally defined oligosaccharides. Due to structure complexity, synthesis of complex carbohydrates with special linkages and configurations by chemical synthetic approaches continue to pose challenges in spite of the significant advances in the field. Enzymatic synthesis by glycosyltransferases is considered an alternative solution. Chemoenzymatic synthesis combining the advantages of the flexibility of chemical synthesis and the high efficiency, regio- and stero-selectivity of enzymatic synthesis is a method of choice to obtain complex carbohydrates and glycoconjugates.