['This study aimed to investigate the effects of serine threonine kinase Pim-3 on the growth of HepG2 cells and to explore the role of STAT3 signaling pathway.', 'Synthetic Pim-3shRNA and negative control shRNA were independently transfected into HepG2 cells in the presence of Lipofectamine(TM) 2000. Cells were divided into 4 groups: Pim-3 shRNA group, negative control group, liposome control group, and blank control group. Flow cytometry was performed to detect the apoptosis of these cells; RT-PCR was employed to detect the mRNA expression of Pim-3; Western blot assay was done to measure the protein expression of Pim-3, STAT3, pSTAT3(Tyr705), Bcl-Xl, Bad and pBad(Ser112).', 'When compared with blank control group, liposome group and negative control group, the apoptosis index increased and the protein expression of Pim-3, pSTAT3(Tyr705), Bcl-Xl and pBad(Ser112) and the Pim-3 mRNA expression reduced in the Pim-3 shRNA group, but the protein expression of STAT3 and Bad was comparable among groups.'] Does serine threonine kinase Pim-3 regulate STAT3 pathway to inhibit proliferation of human liver cancers?