Abstract: In this study lignin and hemicellulose of mulberry tree branch were modified and stripped by acetylization in DMSO/NMI under room temperature.Influence of acetic anhydride dosage,reaction time and solvent dosage on the effect of stripping were studied and its mechanism was also discussed. The results showed that the suitable modification and stripping condition was as follows:acetic anhydride 30 mL, solvent 120 mL, reaction time 24 h. The effect of acetylated modification and stripping of lignin was closely related with acetylating degree and dissolving ability of lignin derivative. The stripped lignin and hemicellulose derivatives degraded slightly.The accessibility of cellulose was improved.