Abstract: Objective To find a way with higher sensitivity and specificity for the diagnosis of tuberculosis (TB).Methods A total of 110 patients were enrolled in this study.The sensitivity and specificity of a T lymphocyte spot assay (T-SPOT.TB) were evaluated in the diagnosis of TB.One hundred and four patients were examined with PPD skin test.Results Of 66 TB patients, 56 were positive with T-SPOT. TB testing, its sensitivity was 84.85%. Forty two of 61 TB cases were PPD positive, its sensitivity was 68.85%. The difference between these two methods have statistical significance(χ²=7.76,P<0.05). Of 44 patients with non-TB diseases, 39 were negative with T-SPOT. TB test, its specificity was 88.64%. Forty three of 44 non-TB cases were examined with PPD skin test, 31 cases were PPD negative, its specificity was 72.09%. Their difference is statistically significant (χ²=4.72,P<0.05). The positive predictive values of T-SPOT.TB assay and PPD skin test were 91.80%(56/61)and 76.36%(42/55), respectively. The sensitivity and specificity of T-SPOT.TB testing were significantly superior to that of PPD skin test.Conclusion T-SPOT.TB assay had higher clinical value on diagnosis of TB.