An enzymatic synthesis of sugar ester from 1,2-o-isoprylidene-D-xylofuranose and fatty acid was studied. Optimal conditions for ester synthesis catalyzed by lipase were established. Lipases N-435 and IM resulted in the highest extent of esterification. The optimum temperature for the sugar ester synthesis reaction by lipase N-435 was 60 degrees C. When the arachidonic acid to 1,2-o-isopropylidene-D-xylofuranose ratio was 1-2:1, a maximum conversion of 83-85% was obtained. After the reaction, the enzyme was easily separated and recovered for reuse. The chemical structure of the sugar ester was confirmed to be xylose 5-arachidonate by nuclear magnetic resonance and mass spectrometry.