［Abstract］ObjectiveTo investigate the occurrence, prognosis and pathogenic distribution of  infections associated with hematological malignancies.MethodsInfections  in  980 inpatients with hematological malignancies between  January，2000 and August， 2008 were analyzed retrospectively. ResultsAmong 980 inpatients,463(47.24％ )cases of infections developed，138 (29.81%) of which were communityacquired infections, 325(70.19%) were  nosocomial infections (NI). Among pathogens causing NI, 387 (55.68%) strains  were gramnegative bacilli, 194 (27.91%)   were grampositive cocci,114(16.40%) were  fungi. Infections occurred most frequently in upper respiratory tract(35.06%) and lower respiratory tract(16.36%). The fewer neutrophil counts were, the more infections developed (P<0.05); infection increased with the  prolongation of hospital stay (P<0.05). ConclusionPatients with hematological malignancies have high infection rates, the majority are NI; the main pathogens are  gramnegative bacilli ;infections are associated with neutrophil counts and hospital stay.