Abstract: Objective To explore the risk factors affecting treatment failure of new smear positive pulmonary tuberculosis in order to provide recommendations for reducing treatment failure. Methods This is a 1∶1 case-control study. 367 treatment failure cases of new smear positive pulmonary tuberculosis registered from 2003 to 2009 in Guangzhou City were selected in the case group; control cases are matched on living district, gender, and age and treatment completion date. Univariate and multiple conditional Logistic regressions were made for analysis. Results 22 significantly different factors are identified through univariate analysis, among which, the top ten factors with higher OR value are irregular medication (19.54), doseager eduction (7.92), smear-positive at the end of 3 months (7.88), liver function damage (7.79), endobronchial tuberculosis (6.05), smear-positive at the end of 2 months (5.17), primary drug-resistant (4.26), hypoalbuminemia (3.01), self management (2.91), diabetes (1.84); Thirteen factors are selected into the regression equation. Among them, factors with higher OR value are irregular medication (15.93), dosage reduction (8.91), primary drug-resistant (5.02), smear-positive at the end of 3 months (3.21), adverse drug response (2.30), smear-positive at the end of 2 months (2.70), Among them, economic status (1.51) is a protective factor. Conclusion irregular medication, dosage reduction, primary drug resistance, smear positive at the end of 2,3 month, adverse drug response are the main factors of treatment failure, the economic situation is protective factor. It is important to adopt corresponding intervention measures against the risk factors in order to reduce treatment failure.

Key words: tuberculosis, pulmonary/drug therapy, treatment failure, risk factors, case-control studies