Abstract: A quantitative thin layer chromatography method was established in this study to determine the concentration of oligosaccharides in curdlan hydrolyzate according to the absorbance of color materials at 540nm.Then, based on this method, an endo-β-1, 3- glucanase (EndoG) was purified to unity from Trichoderma reesei product by means of anion exchange chromatography combining with two- stage size exclusion chromatography process.The purification fold of 44.5 and enzymatic yield of 12.4% were achieved at the final step.The molecular weight of EndoG was 23.6ku.According to the substrate specificity and hydrolysis pattern, EndoG was classified into EC3.2.1.39.Results indicated that laminaribiose and laminaritriose were the major products released from curdlan hydrolyzate and the optimal pH and temperature were 5.0 and 50℃, respectively.A further investigation of EndoG will favor the utilization and application of water- insoluble curdlan due to the definite hydrolysis activity of EndoG on curdlan.