Abstract: Fractional separation of bamboo fiber was studied. With ethanol as solvent, the suitable conditions of fractional separation are 2.1% of NaOH and 1.5% of H₂O₂ in the first fractional separation, 2.4% of NaOH and 2.0% of H₂O₂ in the second fractional separation and 2.4% of NaOH and 1.0% of H₂O₂ in the third fractional separation. Effects of NaOH on the structures of hemicellulose, lignin and cellulose gradually decrease, while H₂O₂ has little influence on it. Ethanol can simultaneously extract lignin and hemicellulose, while ethyl acetate and acetone can't extract hemicellulose. The higher yield and purity of lignin extracted by ethyl acetate are achieved. Ethanol and acetone have little influence on the structures of cellulose and lignin, while ethyl acetate has a great influence on it.

Key words: bamboo fiber, fractional separation, extraction condition