Objective To explore the pathogen spectrum, drug resistance rate and clinical characteristics of pneumonia caused by non-tuberculous mycobacteria (NTM) in acquined immuno-deficiency syndrome (AIDS) patients.Methods The clinical data of 31 hospitalized AIDS patients with bronchoalceolar lavage flind (BALF) culture confirmed NTM pulmonary disease in Guangzhou No.8 People′s Hospital from January,2008 to February,2015 were retrospectively analyzed, including pathogen spectrum, drug resistance rate and clinical characteristics.The clinical characteristics and drug resistance were compared between Mycobacterium avmm-intracellulare complex (MAC) pneumonia and the non-MAC pneumonia, and t test and chi-square test were used.Results Of the 31 AIDS patients,28 were male and 3 were female, with the mean age of 40.9 years old.The 31 NTM strains were consisted of 14 MAC strains and 17 non-MAC strains (including 4 M.kansasii strains,3 M.lentiflavumstrains, 2 M.szulgai strains, 2 M.yongonense strains etc).There was no significant difference between two groups in sex ratio, mean age, clinical manifestations, laboratory tests and treatment outcome (all P>0.05).The major clinical manifestations included fever, productive cough, weight loss, anemia and low CD4+ count (<50/μL).Most patients showed thoracic lymphadenectasis and patchy shadows in lungs, and few patients had millet shadows and pericardial effusion.Compared with non-MAC strains, MAC strains had higher drug resistant rate of moxifloxacin (10/14 vs 4/17), levofloxacin (14/14 vs 8/17), and clarithromycin (11/14 vs 7/17).More extensively drug resistance strains were seen in non-MAC strains compared with MAC strains (11/14 vs 7/17).Conclusions MAC is the most common pathogen of NTM pulmonary disease in AIDS patients.The clinical features of pneumonia caused by MAC and non-MAC are similar, but drug resistance of MAC strains are more severe.