VEGF receptor, KDR, is one of the main VEGF receptors, and it plays important role in VEGF stimulating endothelial cell (EC) proliferation and vascular permeation. To obtain active recombinant KDR which can bind VEGF in vitro, RT-PCR was used to clone KDR (Ⅰ～Ⅳ) DNA fragment from human umbilical vein EC. The cloned KDR (Ⅰ～Ⅳ) fragment was identified with enzyme digestion and sequencing and then cloned into fusion protein expression vector pGEX2T. The GST-KDR fusion proteins were expressed in E.coli XL1-blue after inducing by IPTG. The fusion proteins were extracted from bacterial inclusion body with basic denature method and purified with preparing SDS-PAGE gel followed by electric-elution.