Commercial sodium lignosulfonate from conifer black liquor (RSL) was used hi our study to investigate acid catalyzed hydrolysis of lignosulfonate (LS) by inorganic acids in aqueous solution. Before the hydrolysis process, RSL was purified by alcohol -water solution. Combustion method and gel permeation chromatography (GPC) of the high performance liquid chromatography system (HPLC) were used to detect the purification efficiency. The results showed that methanol -water solution had better purification effect. In addition, for the purified RSL (PSLM), 0.5 mol/L NaOH solution was chosen as the best dissolving medium through the comparison of aggregation behaviors of PSL-M in deionized water and various concentrations of NaOH solutions. In the following acid catalyzed hydrolysis process, the experimental results proved that the three kinds of inorganic acids (HCl, H2SO4 and H3PO4) could catalytically hydrolyze PSL-M to lower molecular weight fractions and other organic chemicals, but HC1 had the best efficiency. Moreover, in 0.5 mol/L NaOH solution, PSL-M (solid-liquid ratio, 50 g/L) catalytically hydrolyzed by 0.68 mol/L HC1 at 50 degrees C for 10 min could produce 1.729 g/kg isovanillic acid, 0.088 g/kg vanillin, 0.007 g/kg syringaldehyde, 0.056 g/kg acetosyringone and 0.024 g/kg acetovanillone respectively.