The human normal liver cells (L-02) were transfected with plasmid pXJ41-neo and pXJ41-PKCα respectively by lipofectamine agent and were selected positive clones by using G418. The analysis of RT-PCR and Western blot showed that the cell model overexpressing PKCα was constructed successfully. In contrast of control cells (LTC) transfected with pXJ41-neo, the PKCα overexpressing cells (LT3) have enhanced growth rate. The RT-PCR analysis showed that the LT3 cells have elevated transciption level of Ha-ras gene and the luciferase assay showed that Ha-ras gene promoter activity increased, in which the prasGL3 plasmid containing Ha-ras promoter was constructed. On the contrary, the BEL-7402 cells (HT6) transfected with antisense PKCα displayed the decrease of growth rate, Ha-ras gene transciption level and Ha-ras promoter activity compared with the control cells (HTC). The results suggested that the effect of PKCα isoform on Ha-ras oncogene expressing was related with the Ha-ras promoter activity. It seems that PKCα play a positive role in Ha-ras gene expressing regulation.