Vascular endothelial growth factors (VEGFs) are a family of proteins that promote angiogenesis and participate in a variety of physiological and pathological processes. In this work, the gene encoding the human VEGF isoform 165 ($hVEGF_{165}$) was cloned into the expression vector pET32a (+) to construct a fusion expression plasmid that induced the thioredoxin (Trx) gene and transformed into Escherichia coli. The recombinant fusion protein Trx-$hVEGF_{165}$ was expressed optimally as inclusion bodies in the case of being cultivated for 4 h at $30^{circ}C$ and 1 mM IPTG concentration. The Trx-$hVEGF_{165}$ was refolded and purified effectively from urea-solubilized inclusion bodies by the immobilized metal affinity chromatography. Released from the fusion protein by enterokinase cleavage and purified to homogeneity, the recombinant $hVEGF_{165}$ ($rhVEGF_{165}$) was biologically active as assessed by the human umbilical-vein endothelial cells (HUVECs) proliferation and the chicken chorioallantoic membrane (CAM) assay. The expression and in vitro refolding of $rhVEGF_{165}$ resulted in production of an active molecule in a yield of 4.04 mg/L flask cultivation.