Capsaicin 4-O-β-xylooligosaccharides were synthesized by a biocatalytic xylosylation using Aspergillus sp. β-xylosidase. Capsaicin was converted into three new capsaicin glycosides, i.e. capsaicin 4-O-β-xyloside, capsaicin 4-O-β-xylobioside, and capsaicin 4-O-β-xylotrioside in 15, 12 and 10% yield, respectively. All products were isolated from the reaction mixtures by preparative HPLC. The structures of the products were determined by NMR spectroscopic method.