Depolymerization of the cellulose component of lignocellulose to glucose is one of the most vital steps for lignocellulose biorefineries. In this report, a self-catalyzed hydrolysis strategy was successfully applied for the selective depolymerization of the cellulose component of wheat straw. After removal of most part of the hemicellulose component by high-pressure CO2-H2O in the presence of acetic acid, the biomass was oxidized by molecular oxygen to convert partial hydroxymethyl groups on glucose units of cellulose to carboxyl groups. The generated acid sites act as the catalytic active centers for the following depolymerization of the cellulose component. As high as 41.6% yield of glucose was obtained in water at 170 degrees C for 6 h without additional catalyst. Additionally, a high ratio of biomass to water (10 wt %) was suitable for this method.