Objective To studyt the clinical characteristic and imaging findings of pulmonary infection in adult HIV/AIDS.Methods The clincial date of 12 pulmonary infection with HIV postive who were treated in Changhai Hospital from January 2004 to May 2011 were analyzed, including the clincial profiles, immunological status, chest radiological characteristics.Results all were men and almost had a CD4 count less than 100 cells/mm3, average age was (41.42±7.92) years old.75% were misdiagnosed as diffuse interstitial pneumonia.The symptoms included cough (50%), fever(66.7%), shortness of breath(75%).Typical imaging findings were bilateral diffuse ground grass opacities distributing in perihilar regions ,which were more often find in PCP.Conclusion Timely treatment is recommended in patients with typical imaging findings , clinical manifestations and positive HIV antibody when other immunodeficient because of the sever immunosuppression, the clinical symptoms and appearence of chest radiological charcteristics are not so typical.HIV antibody test should be taken for the person who has the symptom of fever, cough and cough with less sputum, and diffuse interstitial changes in the chest X ray or CT scan.