The starting material for enzymatic synthesis of azido-SSEA4 (stage-specific embryonic antigen-4) 5-azidopentyl-ß-D-galactopyranosyl-(1-4)-ß-D-glucopyranoside was synthesized chemically. The aim of my research is to make time course tracking to each of the enzymatic reaction steps, to purify their products, and to discuss the cause of inhibition towardsthe enzymatic synthesis of SSEA4.