Objective To study CT features of non-tuberculous mycobacterial(NTM) pulmonary desease in AIDS patients and to explore the different chest CT findings between AIDS-NTM and AIDS-TB patients,in order to improve the correct diagnosis rate of mycobacterial lung disease in advanced AIDS patients.Methods CT findings of twenty-seven AIDS patients with NTM pulmonary disease(NTM group) were retrospectively compared with that of thirty AIDS patients with tuberculosis(TB group) to summarize Computed Tomographic features of NTM pulmonary disease in AIDS patients.The results were statistically analyzed using Fishers exact test.Results CT findings of NTM is significantly higher than that of TB as follows: high-density nodules(18 cases vs 1 case,P = 0.000)、ground-glass opacities(10cases vs 0case,P = 0.000)、fibrotic band(17cases vs 3cases,P = 0.000)、bronchiectasis(9cases vs 2cases,P = 0.012).CT findings of NTM is significantly lower than that of TB as follows:military nodules(0case vs 6cases,P = 0.016)、air space consolidation(2cases vs 11cases,P = 0.009)、pleural effusion(1case vs 9cases,P = 0.010).Conclusion Nodules and fibrotic band were the main thoracic CT manifestations in AIDS patients with NTM pulmonary desease,often acompanied with bronchiectasis;while effusion changes including air space consolidation were the predominate presentations in AIDS patients with pulmonary tuberculosis,often acompanied with Pleural effusion and miliary form.