Objective:To design and prepare siRNAs targeting ski gene and to observe its influence on the biological functions of HepG2 cells,such as proliferation,cell cycle,apoptosis,etc..Methods: Three specific siRNAs of ski were designed and synthesized,and were transiently transfected into HepG2 via cathodolyte liposome transfection method.Real-time PCR and Western blotting were used to measure ski expression at mRNA and protein levels.The cell proliferation was assessed by MTT assay and the changes in cell cycle and apoptosis were evaluated by flow cytometry.Results: All the 3 specific ski-siRNA(A,B,C) effectively inhibited the expression of ski gene,with ski-siRNA-B having the highest inhibition rate(70%).Furthermore,the ski expression had a decreasing tendency with the transfection time.The proliferation of HepG2 cells was markedly inhibited by ski-siRNAs(P<0.05); the number of cells at S stage was obviously decreased,being 2 folds that of the negative control group.Conclusion: The siRNA of ski gene can effectively induce growth inhibition of HepG2 cells and reduce cells of S stage, which is possibly through down-regulation of ski gene.