Objective:To obtain human umbilical vein endothelial cells (HUVECs) that stably expressing KSHV K1 protein and explore the effect of K1 protein on the proliferation and migration ability of HUVECs. Methods:The constructed fragment of K1 gene from expression plasmid pCI-neo-K1 was cloned into the lentiviral vector pHAGE-CMV-MCS-IZs-Green. We co-transfected the recombinant plasmid pHAGE-K1,the packaging plasmid psPAX2 and the envelope plasmid pMD2.G into 293T cells. Culture media were harvested and filtered through a 0.45 μm filter to remove the cells. The expression of K1 protein in recombinant lentivirus-infected HUVECs was detected by Western blot assay. Next,HUVECs stably expressing KSHV K1 protein were obtained by flow cytometry assay (FCM) screening and verified the expression of K1 protein by Western blot assay again. Finally,the effect of K1 protein on the proliferation and migration ability of HUVECs was detected by CCK-8 assay and wound-healing assay. Results:Nucleic acid sequencing confirmed that cloned K1 gene was 906 bp,wihch was 100% homologous with K1 gene registered in GenBank. The exact band of K1 protein in recombinant lentivirus-infected HUVECs was detectable by Western blot assay. The results of CCK-8 and wound-healing assay showed that the proliferation and migration ability of HUVEC stably expressing KSHV K1 protein was significantly increased than the corresponding control(P < 0.01 and P < 0.05,respectively). Conclusion:The recombinant lentivirus carrying KSHV K1 gene was packaged successfully,and K1 protein could promote the proliferation and migration of HUVECs.