LYG-202 (C25H30N2O5) is a newly synthesized flavonoid that has been confirmed to possess an antitumor effect, but the mechanism is unclear. Our present study was performed to identify the anti-angiogenic activity of this novel compound in vitro and in vivo. LYG-202 inhibited vascular endothelial growth factor (VEGF) stimulated migration and tube formation of human umbilical vein endothelial cells and arrested microvessel outgrowth from rat aortic rings in vitro. Meanwhile, LYG-202 suppressed the neovascularization of Chicken Chorioallantoic Membrane in vivo. Mechanistic studies revealed that LYG-202 suppressed the VEGF-induced tyrosine phosphorylation of KDR/Flk-1 (VEGFR-2) as well as its downstream protein kinases activation, by decreasing phosphorylated forms of serine/threonine kinase Akt, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase. LYG-202 exerts anti-angiogenic activity both in vitro and in vivo, and these results suggest that it deserves further investigation as a promising anti-tumor angiogenesis compound.