Objective:To construct the recombinant secretory plasmid containing vIL-6 gene of KSHV,detect its protein expression in EA.hy926 cells,and observe the effect of the secretory protein on proliferation and angiogenesis of vascular endothelial cells. Methods:A pair of PCR primers for vIL-6 gene including HindⅢ and XhoⅠ restriction sites was designed according to the sequence of pvIL-6 F. vIL-6 gene was amplified by PCR, taking pvIL-6 F as template. Then purified vIL-6 gene fragments were digested and cloned into pSecTag2B vector to generate recombinant secretory expression plasmid named as pSecTag2B-vIL-6. pSecTag2B-vIL-6 was transfected into EA.hy926 cells. The expression of vIL-6 protein in EA.hy926 cells was detected by Western blot, and supernatant of 293T cells transfected by the recombinant secretory plasmid was collected, then the effect of vIL-6 on proliferation and angiogenesis of vascular endothelial cells by autocrine and paracrine was detected by cell proliferation assay and microtube formation assay. Results:The recombinant secretory plasmid carrying KSHV vIL-6 gene was constructed successfully. After transfected with the above plasmid, the exact band of vIL-6 was detectable by Western blot. EA.hy926 cells treated either with supernatants collected from 293T cells transfected by recombinant secretory plasmid or with transient transfection of the recombinant secretory plasmid, could perform an enhancement in proliferation and angiogenesis. Conclusion:The recombinant secretory plasmid pSecTag2B-vIL-6 was constructed successfully, and vIL-6 protein could be correctly expressed in EA.hy926 cells. Importantly, vIL-6 protein could promote the proliferation and angiogenesis of vascular endothelial cells through autocrine and paracrine pathway.