A condensation reaction between N-acetyllactosamine and glycerol was directly catalyzed by using a commercially available cellulase preparation from Trichoderma reesei. 1-O-β-N-Acetyllactosaminyl-(R, S)-glycerols (1) were readily synthesized in a 5% yield based on the N-acetyllactosamine added and conveniently isolated by two-step column chromatographies. The use of a partially purified enzyme increased 2.3-fold the yield of 1, compared to that of the crude enzyme containing β-D-galactosidase activity. When various alkanols (n:2-4) were used in the condensation reaction, the corresponding alkyl β-N-acetyllactosaminides were obtained in yields of 0.3-1.1% of the desired compounds.