Abstract： Objective To analyze the correlation of perfusion parameters obtained by functional multi-slice computed tomography (fMSCT) with vascular endothelial growth factor (VEGF) detected with immunohistochemistry on rabbit model with VX2 breast cancer and noninvasively evaluate the vascularization of untreated VX2 breast cancer in vivo. Methods Sixteen New Zealand femal rabbits were selected and suspension (1 ml) of mass was injected around the breast areola. CT perfusion was performed after two weeks and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT)and permeability surface (PS) were assessed. Expression of VEGF in neoplasm was detected with immunohistochemistry. Paried t test was used for the comparison of perfusion parameters between the tumor and muscle and Pearson correlation analysis was used to assess the correlation of VEGF with perfusion parameters. Results The mean value of BF, BV, MTT and PS were (228.21 ± 13. 13 ) ml · min-1100 mg-1 ,(13.45 ± 1.01) ml · 100 mg-1 ,(3. 50 ±0. 20) sand (7.85 ±1.18) ml · min-1 · 100 mg-1 in tumor, respectively. They were (66. 10 ±22. 11 ) ml · min-1 · 100 mg-1 , ( 1.88 ± 1.80) ml · 100 mg-1,(23. 87 ±0. 63)s,(1.55 ±0. 38)ml · min-1 · 100 mg-1 in muscular tissue, respectively. The mean value of BF, BV and PS in tumor were obviously higher than those in muscle, and the mean value of MTT in tumor was lower than that in muscle. There were significant differences in CT perfusion parameters between tumor and muscle (t = 61.83,13.63,27.72,20. 54, P ＜ 0. 01 ). The mean value of VEGF in tumor was 7. 33 ±0. 27 and there were positive correlation with BF ( r = 0. 712, P ＜ 0. 01 ), BV ( r = 0. 647, P ＜ 0. 01 ), PS ( r =0. 627 ,P ＜ 0. 01 ), and negative correlation with MTT ( r = - 0. 564, P ＜ 0. 05 ). Conclusion MSCT perfusion imaging can be used to noninvasively evaluate the vascularization in rabbits with untreated VX2 breast cancer in vivo.