Objective Discussion about value of brain natriuretic peptide (BNP) in helping to determine the efficacy and prognostic of pulmonary tuberculosis combine with respiratory failure. Methods 81 cases were admitted from January 2013 to December 2014 in our hospital of early treatment sputum positive pulmonary tuberculosis with respiratory failure. And the cases were carried out BNP, arterial blood gas analysis and chest X-ray before treatment and after two weeks respectively.104 cases of earlier sputum positive pulmonary tuberculosis accompanied with respiratory failure were randomly drawn according to the corresponding random number of hospitalization as a control group. Two sets of data were collected to conduct retrospective case-control study. Results BNP of pulmonary tuberculosis combine with respiratory failure is 11.4 times higher than that of tuberculosis alone (1115.11 pg/mL compare 97.60 pg/mL), the whole TB is 3.4 times higher than non-full-tuberculosis (1549.82 pg/mL t compare 449.47 pg/mL). Before treatment, BNP was negatively correlated to PaO₂, SaO₂ and pH BNP was positively correlated with PaCO₂. There was no correlation after treatment between BNP and PaCO₂.After two weeks BNP is 0.57 times of the pre-treatment (632.41 pg/mL compared 1115.11 pg/mL). The group of death is 8.7 times higher than the survival group (3119.63 pg/mL compared 359.84 pg/mL). Conclusion BNP was significantly increased in patient accompanied tuberculosis with respiratory failure .The condition is continued to decline after treatment. There is likely to be one of the indicators of helping to determine the efficacy and estimate prognosis.