Abstract: Sugarcane bagasse(SCB) was pretreated by hydrogen peroxide-acetic acid(HPAC). The pretreated SCB was used as raw material for enzymatic hydrolysis, and then the hydrolysate was fermented for ethanol. The effects of pretreatment on enzymatic hydrolysis and fermentation of SCB were discussed. The results showed that HPAC pretreatment removed 88.85% lignin and retained 90.10% cellulose in the substrate when 20 g SCB was added with 150 mL aqueous hydrogen peroxide(i.e., 75 mL hydrogen peroxide(30%) and 75 mL water) and 150 mL acetic acid(99%), the amount of sulfuric acid was 0.5% of the HPAC solution volume, and the reaction was preformed at 70 ℃ for 2 h. The enzyme accessibility of substrate was 80.30 mg/g, which increased by 38.26% and 31.08% compared with those of hydrogen peroxide pretreatment (HP/70-SCB) and acetic acid pretreatment(AC/70-SCB) under the same conditions, respectively, and the surface coverage of lignin decreased from 0.66 to 0.22. After hydrolysis with enzyme dosage of 5 FPIU/g(substrate), the yield of glucose was 87.63%, which was 6.89 and 20.62 times than those of HP/70-SCB and AC/70-SCB, respectively. The mass concentration of ethanol produced by fermentation was 7.57 g/L, which was 7.65 and 22.94 times than those of HP/70-SCB and AC/70-SCB, respectively.