Abstract: Object To evaluate the value of fiberoptic bronchoscopy to the lower lung field tuberculosis with sputum smear negative.Method 26 cases with lower lung field shadow and sputum smear negative were chosen for bronchoscopy.Results Major finding detected by fiberoptic bronchoscopy were:tuberculous granuloma;mucosae congestion and edema;bronchiole stomatal stenosis.TBLB was performed in 12 cases.Tuberculous granuloma was found in 8 cases with the positive rate of 66 7%.M.tuberculosis bacterium was found in 5 cases(19.2%,5/26)by brush smear or BALF.The general positive diagnosis rate was 84.6%.Conclusion Fiberoptic bronchoscopy plays an important role in the diagnosis of lower lung field tuberculosis.

Key words: Tuberculosis, pulmonary, Diagnosis, Fiberoptic bronchoscopy