Abstract： Objective To evaluate the application of enzyme-linked immunospot assay (T SPOT) in diagnosis of Mycobacterium tuberculosis (MTB) infection for AIDS patients. Methods The rapid T SPOT assay was employed to detect ESAT-6 and CFP-10 specific T cells in blood samples from 35 AIDS patients with active tuberculosis. The results were compared with those of PPD skin test. Results The positive-MTB rate with T SPOT assay in all patients (n = 35 ) was 65.71%, that in patients with CD4 < 200/μ (n = 21) was 66.67%, in patients with CD4 > 200/μl (n = 10) was 60.0% , in patients with anti-tuberculosis treatment < 2 months ( n = 15 ) was 83.33% and in patients with treatment > 2 months ( n = 6 ) was 25.00%. The positive rates of PPD skin test were 24.24%, 25.00%, 33.33%, 9.09% and 25.00% in these groups, respectively. The positive rates of T SPOT assay were significantly higher than those of PPD skin test in all patients, in those with CD4 < 200/μl and with anti-tuberculosis treatment < 2 months ( P < 0.05 ). Conclusion T SPOT assay was more sensitive than conventional PPD skin test, and can be applied in the diagnosis of MTB infections for AIDS patients.