Abstract: In order to analyze the structural characteristics of lignin of Dendrocalamus sinicus Chia et J. L. Sun,the lignin and hemicelluloses were isolated by organic-inorganic sequential extraction.Dewaxing bamboo powder was sequentially extracted with 80% dioxane,80% dioxane-0.5% NaOH,2% NaOH aqueous,5% NaOH and 8% NaOH,respectively.Five lignin samples(L1-L5) were obtained,and the yields of lignin were caculated.The structural features of the isolated bamboo lignin fractions were characterized by FT-IR,UV,13C NMR and 2D HSQC.The analysis results indicated that 70.6% original lignin was fractionated from D. sinicus after five-step treatments,and the highest purity lignin sample was L2.This indicated this method was an effective method to isolate lignin.The structure of lignin was saved during the separation process,but a part of ester linkages were broken due to the alkaline surroundings.In addition,the lignin polymer isolated from D. sinicus consisted of guaiacyl,syringyl and p-hydroxyphenyl units.The inter-units linkages presented in the bamboo lignin including β-O-4' linkages, β-β' linkages, β-5' and β-1' linkages.