Abstract: Objective To investigate the expression of long non-coding RNA XLOC_004122 in bronchoalveolar lavage fluid of patients with pulmonary tuberculosis (TB), and its diagnostic value for TB. Methods A total of 45 bronchoalveolar lavage fluid samples collected from the 309th Hospital of Chinese PLA from October 2014 to March 2015 were divided into XLOC_004122 high group and XLOC_004122 low group according to the results of real-time quantitative PCR, and the clinical outcomes were compared between the two groups. Results Sputum culture conversion rate was significant higher in XLOC_004122 low group comparing with XLOC_004122 high group (at 3 weeks after treatment, 75.00% vs 39.00%, P< 0.05). Meanwhile, colony forming units count in sputum culture was significant lower in XLOC_004122 low group than that in XLOC_004122 high group (at 3 weeks after treatment, 0.78±0.03 vs 1.33±0.05, P< 0.05). Conclusion These findings indicate that XLOC_004122 can be used as a prognosis predictor for pulmonary tuberculosis.