Objective To evaluate the diagnostic value of Tuberculosis Infection in T Cell Test(T‐SPOT .TB) for smear negative pulmonary tuberculosis .Methods Separately used T‐SPOT .TB ,TB‐DNA ,TB‐DOT the three diagnostic methods for tuberculosis , separately detected with each method ,112 smear negative pulmonary tuberculosis ,and 60 non tuberculosis regarded as control group .Results The sensitivity of T‐SPOT .TB ,TB‐DNA ,TB‐DOT in proper sequence were 88 .3% ,25 .9% ,58 .9% .Contrasted to TB‐DNA and TB‐DOT ,the differences were statistically significant(X2 =86 .6 ,P<0 .01 ;X2 =23 .3 ,P<0 .01);the specificity of T‐SPOT .TB was 96 .7% ,significantly higher than TB‐DOT (78 .3% ) ,the differences were statistically significant(X2 = 9 .22 ,P<0 .05) .Conclusion T‐SPOT .TB has obvious advantages in sensitivity and specificity for smear negative pulmonary tuberculosis .It can be one auxiliary tool for smear negative pulmonary tuberculosis early diagnosis ,provided with the value of fast and accurate .