OBJECTIVE To analyze and summarize the clinical features and distribution of antibiotic susceptibility of Stenotrophomonas maltophilia pneumonia.METHODS We statistically analyzed the clinical data of thirty-one cases of S.maltophilia pneumonia,and determined drug susceptibility of this bacteriaum,using K-B methods.RESULTS Twenty-six out of 31(83.87%) cases were old age patients.All Patients were with underlying diseases,while 17(54.84%)cases had chronic obstructive pulmonary disease history and 15(43.39%) cases were with immunodeficiency.Out-of hospital infection and nosocomial infection were 10(32.26%) cases and 21(67.74%),respectively.The clinical symptoms were mainly cough and expectoration(100.00%),17(54.84%) cases had fever,and 24 cases(77.42%) had dyspnea.Chest X-ray showed different-degree shadow on lungs.Besides compound sulfamethoxazole,ciprofloxacin,minocycline and amikacin were susceptive(71.41-45.00%),the drug susceptibility test showed,that the microbe was resistant to lots of antibiotics(28.57-100.00%).CONCLUSIONS The risk factors of S.maltophilia pneumonia are ageing,underlying diseases and immunodeficiency.Early choosing susceptive antibiotics and drug sensitivity test would improve the prognosis.