Communication: A new procedure for chemical modification of poly(vinyl alcohol) (PVA) was established by a glycosidation reaction of hydroxyl groups in PVA with triacetylated sugar oxazoline 1. H-1 and C-13 NMR analyses indicated that triacetylated N-acetyl-D-glucosamine (GlcNAc) was introduced onto a PVA backbone selectively via a beta-O-glycoside linkage. Deacetylation of triacetylated GlcNAc-substituted PVA 2 resulted in GlcNAc-substituted PVA 3 in good yield. These modified PVAs 2 and 3 exhibited solubilities and thermal properties different from the original PVA.