Abstract: OBJECTIVE To investigate the incidence of central line-associated bloodstream infection (CLABSI) in the patients with hematological malignancies and comprehensively analyze the influence of CLABSI on hospitalization cost and length of hospital stay so as to provide health economics bases for scientific control and prevention. METHODS The clinical data were retrospectively collected from the patients with hematological malignancies who were treated in hematology department and stem cell transplantation center of The First Affiliated Hospital of Chongqing Medical University from Jan. 1, 2022 to Dec. 31,2024. The enrolled patients who were divided into the CLABSI group and the non-CLABSI group according to the status of CLABSI. The sex, age, diagnosis of neoplastic hematologic disorders, stem cell transplantation and duration of central venous catheter indwelling were chosen as the concomitant variables so as to establish a balanced database by using 1∶1 propensity matching score. The length of hospital stay and hospitalization costs were observed and compared between the two groups after the matching. RESULTS Totally 3558 patients were enrolled in the study, the number of days of central venous catheter indwelling was 50 813 days; 76 patients had CLABSI, and the incidence of infections was 1.5‰. Totally 74 pairs were matched successfully by propensity matching score. The data analysis showed that the median length of hospital stay of the CLABSI group was increased by 27.5 days as compared with the non-CLABSI group, and there was significant difference(Z=-10.378,P＜0.001); the total hospitalization cost (the median) was increased by 48 522.91 yuan; there were significant differences in all the cost details except for costs of clinical diagnosis and traditional chinese medicine between the two groups(P＜0.05). CONCLUSION The propensity score matching showed that the hematological malignancies patients have heavy disease burden due to CLABSI, and it is extremely necessary to pay attention to the control and prevention.