The inhibitory action and the possible mechanism of anticancer compound Sanguinarine (SAN) on vascular endothelial growth factor (VEGF) in human mammary adenocarcinoma cells MCF-7 were evaluated in this study. We exposed MCF-7 to SAN for 24 h, then cell viability was assessed by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. Human VEGF was measured using a paired antibody quantitative ELISA kit, relative expression of VEGF mRNA was calculated using the real-time PCR studies, and the effect of SAN on the reactive oxygen species (ROS) level was detected by the flow cytometer. Treatment with SAN remarkably inhibited growth of MCF-7 cells and induced cell apoptosis. We found that VEGF release was stimulated by subtoxic concentrations of SAN and inhibited by high dose of SAN, SAN-evoked VEGF release was mimicked by low concentration of H2O2, and SAN-regulated VEGF inhibition was accompanied by increasing of ROS; these changes were abolished by antioxidant. High concentration of SAN inhibited VEGF mRNA expression in MCF-7 cultures, suggesting an effect at transcriptional level, and was also abolished by antioxidant. The present findings indicated that the regulation of VEGF expression and release from MCF-7 cells were possibly through reactive oxygen species evoked by SAN.