提出了测定木素酚羟基含量改进的差示紫外光谱法。该法用水代替二氧六环作溶剂,选用差示紫外光谱中250nm附近的最大吸收峰,建立了模型物的吸收强度与酚羟基含量的线性回归方程式。计算了桦木、芦苇、红松和落叶松的硫酸盐木素的酚羟基含量。最佳工作曲线为ΔA_(max)=5.6×10~3cl+0.21,测定结果与化学法极为接近。测定精度良好,标准偏差不大于0.04。 A differential ultraviolet spectrometry method was developed to determine the hydroxyl content of lignophenol. In this method, water is used instead of dioxane as a solvent, and the maximum absorption peak near 250 nm in the differential ultraviolet spectrum is used to establish a linear regression equation for the absorption intensity and phenolic hydroxyl group content of the model. The phenolic hydroxyl content of kraft lignin of birch, reed, korean pine and larch was calculated. The best working curve is ΔA_(max)=5.6×10~3cl+0.21. The measurement result is very close to the chemical method. The measurement accuracy is good and the standard deviation is not more than 0.04.