Objective To explore the immune status of patients with nontuberculous mycobacterial(NTM) pulmonary disease, and the application of immunotherapy. to evaluate the influence of immunotherapy on sputum negative conversion and lesion absorption at the end of two months. provide reference data for immunotherapy. Methods The immune function and immunotherapy of 381 patients diagnosed as NTM pulmonary disease were retrospectively analyzed from January 2014 to December 2015 in Guangzhou Chest Hospital. Curative group (treated with antitubercular agents and immunomodulator mycobacterium vaccae) were compared with control group(treated with antitubercular agents alone) in sputum negative conversion and lesion absorption at the end of two month treatment. Results Of the 381 cases,45.67%(174／381)of the patients were immunocompromised, 59.84% (228／381)received immunotherapy. Bacteriologic changes: Both sputum smear and sputum culture were positive in all patents before treatment. after two months treatment, negative conversion in two groups were 67／228(29.38%),17／153(11.11%),χ²=17.79,P<0.05. 3. Radiological change: The rate of lesion absorption in curative group and control group were respectively 62／228(27.19%),16／153(10.45%),χ²=15.75,P<0.05;The rate of promoting cavity closure were respectively 61／228(26.75%),15／153(9.80%),χ²=20.42,P<0.05. Conclusion The immune function of NTM pulmonary disease had high ratio of being compromised. Curative group showed a significant effect of sputum negative conversion, lesion absorption and promoting cavity closure compared to the control group. Added to chemotherapy, M. vaccae is helpful in the treatment of nevertreated TB patients in terms of improving both Immunotherapy with M. vaccae had a beneficial influence on sputum negative conversion and X-ray appearances.