目的：分析血液科住院患者细菌感染的特点，为临床治疗提供病原学依据。方法： 回顾性分析2011年1月至2013年12月北京大学第三医院血液科院内感染患者的细菌菌种及其耐药性,送检标本来源为血、中段尿、咽拭子、痰等。结果： 共培养菌株168株，来自痰标本最多，为72株(42.9%)，其中革兰阴性菌114株（67.9%），革兰阳性菌54株（32.1%），主要致病菌为铜绿假单胞菌(20.8%)、大肠埃希菌(18.5%)、金黄色葡萄球菌(17.9%)、肺炎克雷伯菌(9.5%)、表皮葡萄球菌(5.9%)，其他细菌占27.4%；革兰阴性菌对头孢吡肟、丁胺卡那及碳青霉烯类药物耐药率低，革兰阳性菌对万古霉素及利奈唑胺保持极低耐药率。结论： 血液病患者是院内感染的高发人群，革兰阴性菌依然为主要致病菌，密切关注病原学特点才能进行有效的经验性抗感染治疗及控制耐药率。

Objective：To analyze the characteristics of hospital infection of hematological disease, so as to provide reference for clinical therapy．Methods: Bacterial strains and antimicrobial resistance of patients with hospital infection in Department of Hematology, Peking University Third Hospital from Jan. 2011 to Dec. 2013 were identified and analyzed retrospectively. The specimens were from their blood, urine, sputum, throat swabs and etc.Results: Among the total of 168 isolates of bacteria，the majority of the bacteria strains were from sputum (42.9%);114(67.9%) bacteria strains were gram negative and 54(32. 1%) bacteria strains were gram positive; the pathogen testing showed that 20.8% were Pseudomonas aeruginosa,18.5% Escherichia coli,17.9% Staphylococcus aureus, 9.5% Klebsiellar pneumonia, 5.9% Staphylococcus epidermis and 27.4% other bacteria ; The gram negative bacilli to cefepime, amikacin and carbapenems showed the lowest antimicrobial resistance rates, and S. aureus showed the lowest antimicrobial resistance rates to vancomycin and linezolid. Conclusion: Patients with hemopathy are the main population of hospital infections, the gram negative bacteria are the most common pathogens．It is very important to promptly know the change in distribution of the pathogens in order to rationally select antibiotics and reduce the incidence of bacterial infections．