Abstract: Objective To investigate the effect of Kruppel like factor 8 (KLF8) overexpression on renal cell carcinoma cell line 769-P proliferation and discuss its possible mechanisms through constructing recombinant lentiviral vector with KLF8 genes. Methods The recombinant lentiviral vector pLV-EGFP (2A) Puro-KLF8 and pLV-EGFP (2A) Puro were individually co-transfected into 293v cells with packaging plasmids pH1 and pH2 to assemble viruses.After 48 hours, viruses were collected and infected with 769-P cells.Real-time PCR and western blot were used to detect the expression of KLF8.The 769-P cells were divided into two groups according to they were infected by the recombined KLF8 viruses or empty vector viruses.The effects of KLF8 on proliferation of 769-P cells were analyzed by Colony-forming assay and MTS, and the changes of potential target gene were detected by western blot. Results After successful construction of the recombined pLV-EGFP (2A) Puro-KLF8 lentiviral vector and transfection into 769-P cell line, the expression of KLF8 upregulated significantly compared with empty vector group.Colony-forming assay showed that after 10 days of culture, compared with control group, the colony number increased significantly in experimental group (P< 0.05).The OD values (490 nm) of experimental group were significantly higher than control group at 48 h, 72 h, 96 h in MTS assay (P< 0.05).Western blot showed no difference of VEGF, VEGFC, VEGFR2 and VEGFR3 between experimental group and control group, except VEGFR1 which was highly expressed in experimental group. Conclusion The overexpression of KLF8 can significantly increase proliferation of 769-P cell line and upregulate VEGFR1.