Vascular endothelial growth factor (VEGF) with paracrine mechanism has recently been identified . Its growth-promoting activity is specific for vascular endothelial cells in vitro, VEGF also stimulates angiogenesis and increases blood vessel permeability in vivo. Because its bioactivity has a direct bearing on the growth of solid tumors, the researches on VEGF have been payed a good deal of attention and made good progress.