The primary goal of this study was optimized condition for hydrolyzed of papermaking waste (poplar sawdust) as a potential bio-ethanol source by sulfuric acid pretreatment. Based on 23 factorial design, fifteen operations were performed by varying on T, t and c (T: hydrolysis temperature, t: hydrolysis time and c: sulfuric acid concentration). The components of the hydrolysate and solid fractions were analyzed by GC, X-RD and SEM, respectively. The results showed that optimal condition was T 44.8°C, t 120min and c 60%, and reducing sugar yield of 43.3% can be obtained. Through GC detection, glucose content of 26.10 g/L and xylose content of 9.00 g/L is available in hydrolyzate for fermentation. The residue crystallinity declined 74.34% from XRD analysis, the fiber structure was destroyed completely by acid hydrolysis from SEM photograph.