Objective To explore the clinical characteristics of and to provide help to the prevention and treatment of malignant chest tumor with nosocomial mixed fungal-bacterial infection.Methods From July 2007 to June 2015,pathogenic bacteria in sputum,blood,urine,chest incision,thoracic and abdominal fluid,and implantable medical biological material were cultivated in 5067 patients with malignant chest tumor suspected with infection.The clinical characteristics,source of specimen and pathogenic bacteria,the types of diseases,medical intervention activities of 142 cases detected with mixed fungal-bacterial infection were retrospectively analyzed.Fesult In 142 patients,104 patients at clinical stage Ⅲ-Ⅳ accounted for 73.2％,and 94 patients used antibiotics more than 14 days (66.2％);104 cases had implanted biological materials (74.7％);96 cases died (67.6％).A total of 167 strains bacteria were isolated.Sixty-one strains of G+ bacteria accounting for 36.5％ were mainly Epidermis staphylococcus and Staphylococcus aureus;106 strains of G-bacteria accounting for 63.5％ were mainly klebsiella pneumonia,Escherichia coli and baumanii;172 strains fungus mainly of Candida albicans were isolated (77.3％).Pathogenic bacteria sources were mainly sputum specimens + pharynx strip,blood culture and medical implant materials.In 72 lung cancer patients,squamous carcinoma and small cell carcinoma were 52.8％ and 33.3％ respectively,higher than adenocarcinoma (12.5％);In 42 esophageal cancer patients,postoperative patients were 42.9％.Parenteral nutrition patients with more than 10 days were 80.9％ higher than that of parenteral nutrition in patients with less than 10 days (19.1％).Conclusion Among malignant chest tumor patients with nosocomial mixed fungal-bacterial infection,the bacteria were found in staphylococcus aureus,klebsiella pneumoniae and E.coli and the fungus was Candida albicans.For clinical stage Ⅲ-Ⅳ,patients with parenteral nutrition for more than 10 days,having history of chemo or radiotherapy,with antimicrobial use for more than 14 days,and with implanted biological materials,should be warned about nosocomial mixed fungal-bacterial infection.