Penicillium oxalicum beta-N-acetylhexosaminidase was found to have transglycosylation activity in addition to hydrolytic activity. The enzyme effectively transferred N-acetylglucosamine to various alcohols in the presence of N-acetylchitooligomers as donors. The enzyme also transferred N-acetylglucosamine to diol-derivatives. Using this transglycosylation activity, a drug carrier, 6-benzyloxyhexyl-beta-N-acetylglucosaminide, was synthesized by incubating the enzyme with 6-benzyloxyhexan-1-ol and N-acetylchitotriose. The product was isolated by silica gel column chromatography and was analyzed by mass-spectrometry and H-1-NMR.