Abstract: To research birch bark extracts' proliferation inhibition in human umbilical vein endothelial cells. The proliferation inhibition of birch bark extracts (BBE) in human umbilical vein endothelial cells (HUVEC) was measured by MTT assays. Expression of VEGFmRNA was measured by PCR. VEGF was measured by ELISA. Cell growth was obviously suppressed in the BBE treated groups. 150 μg/mL group was significantly different from control group. Realtime PCR reveales that BBE treated groups cause the expression ratios of VEGFmRNA decreased from 1 to 0.125(75 μg/mL) and 1 to 0.05(150 μg/mL) in 48 h. ELISA showes that high concentration BBE treated group leads to significant reduction in the levels of VEGF. BBE inhibited the proliferation of HUVEC through inhibiting intracellular expression of VECF mRNA and secretion of VECF.