To obtain an efficient and green reaction system for the production of furfural (FF), this study investigated the use of a SO3H-finactiopgized ionic liquid as a catalyst for the conversion of xylose in a solvent of renewable gamma-valerolactone (GVL). A high FF yield of 7842% was obtained in this reaction system catalyzed by 1-propylsulfonic-3-methylimidazolium chloride at 140 degrees C. The GVL remarkably enhanced the reaction rate and increased the xylose conversion and FF yield because the solvent effect of GVL, could improve the catalytic activity of the acidic protons and suppress the side reactions. In addition, the ionic liquids showed satisfactory catalytic performance in the conversion of xylose to FF due to functionalization by introducing a SO3H group. The conversion of, other CS carbohydrates (arabinose and xylan) was also tested in this system, and moderate FF yields were achieved.