Abstract: To explore the diagnostic method of pulmonary tuberculosis(PTB), the following methodsbacterial examination of tubercle bacill in sputum by acid fast staining technique was studied by smear acid fast staining technique(TB smear), polymerase chain reaction technique, PPD skin test and determination of antimycobacterial antibody level in the patient blood were utilized for diagnosing PTB. The results showed: The specificity of diagnosing PTB reached 100%, but the its sensitivity was very low(22.2%)by using TB smear. The other three methods were a little better in sensitivity, but were too bad in specificity. This suggested: The reliable diagnostic method of PTB is still a TB smear, however, the sensitivity is no good. The other three methods have limited value in diagnosing PTB.

Key words: pulmonary tuberculosis, TB smear, PCR, PPD, determination of antimycobacterial antibody level in the blood