Abstract: Objective:to evaluate the effect about 11 antigen-preparations used for serological differential diagnosis of pulmonary tuberculosis and lung cancer.Methods:With ELISA we measured the antibodies against 11 antigen-preparations in sera from 104 patients with pulmonary tuberculosis, 104 patients with lung cancer and 52 healthy controls respectively. Results:The positive rate of the antibody in sera of patients with pulmonary tuberculosis against Antigen B6b which was a cell ultrasonic prepartion from Mycobacterium scrofulaceum was 82%, which is significantly higher than 62% of positive antibody against PPD （P＜0.05）;1.9% of sera from lung cancer had positive antibody against B6b and 15.4% of sera from lung cancer had positive antibody against PPD, the difference was very significant （P＜0.01）.Conclusion:The species, culture method and preparation method of the antigens from Mycobacterium had an important influence on the specificity and sensitivity in serological diagnosis. Among these antigens, B6b gave the best effect in the differential diagnosis.