This work aims at the valorization of sugarcane bagasse by extracting xylose which is destined to the production of xylitol after purification and hydrogenation. Our approach consists in applying the principle of biorefinery to sugarcane bagasse because of its hemicellulose composition (particularly rich in xylan: (92%)), Optimizing of the thermal treatment was investigated. A treatment at 170 C for 2 h was found optimal, with higher solubilzation of hemicellulose than that at 150 C and lower degradation of sugar monomers than 190 degrees C. Recovery of xylose was high and the purity of xylose solution (78%) allows expecting an easy purification and separation of xylose before hydrogenation. Analysis of thermal hydrolyzates shows the presence of xylan oligomers and polymers with large distribution of DPs. This fraction should be submitted to enzymatic treatment to recover more xylose monomer. (C) 2009 Elsevier Ltd. All rights reserved.