Objective: The aim of this study was evaluate the diagnostic value of computed tomography (CT) perfusion in breast cancer by the method of receiver operator characteristic curve (ROC) analysis. Methods: Eighty-one cases with breast masses found by health examination or mammography were scanned by multi-slice spiral CT (MSCT) perfusion and hemo-dynamic parameters of blood flow (BF), mean transit time (MTT) and blood volume (BV) were calculated by deconvolution arithmetic. According to the pathologic results, two groups, benign and malignant were classified and statistical analysis were performed between them. The ROC characteristics of BF, MTT, BV were compared for each and the diagnostic value of the hemodynamic parameters were confirmed. Results: In the malignant group, BF was (0.735±0.440) mL/min/mL, MTT was (22.771±7.647) s and BV was 0.234±0.082. In the benign group, BF was (0.466±0.527) mL/min/mL, MTT was (26.712 ±12.934) s and BV was 0.179±0.117. There was a significant difference for BF and BV between the benign and malignant groups. When the hemodynamic parameters were used to discriminate the breast lesions, the area under the ROC curve (AUCROC) of BF was 0.832±0.086, the maximum, while AUCROC of BV was 0.695±0.092. There was no significant statistical difference between BF and BV. AUCROC of MTT was 0.473±0.102, which was minimal. Since the threshold of BF was 0.381 mL/min/mL, the sensitivity was 82.3%, the specificity was 73.2%, the positive likelihood ratio (LR) was 3.071 and the negative LR was 0.242. The threshold of BV was 0.190 with sensitivity 73.3%, specificity 56.5%, positive likelihood ratio 1.685 and negative LR 0.473. Conclusion: BF and BV among CT hemodynamic parameters have certain diagnostic value in breast cancer, but BF or BV can not yet be single index to confirm or deny the diagnosis.