Abstract: Objective：To explore the influences of cyclin dependent kinase(CDK) on proliferation and apoptosis in hepatic carcinoma cells. Method： After interfered by roscovitine of 0 μmol/L、2 μmol/L、4 μmol/L、8 μmol/L、16 μmol/L 、32 μmol/L for 72 hours, inverted microscope，MTT， flow cytometry and reverse transcription-polymerase chain reaction （RT-PCR） were used to observe the effects of CDK on growth， proliferation， cell cycle，apoptosis and the mRNA expression of caspase-3，BCL-2 in SMMC-7721 cells cultured in vitro. Results：After interfered by roscovitine for 72 hours, the microscope showed that a part of nucleus became pyknotic, the cytosome refractivity weakened, particles and nuclear debris appeared in cytoplasm with the increase of roscovitine concentration, and the effect of roscovitine in 32 μmol/L was the most remarkable. The results of MTT also showed that the roscovitine could inhibit the growth of cells with various dose, and the inhibition was dependent on dosage and time. Flow cytometry observed it also could increase the ratio of G0、G1 and apoptotic cells. RT-PCR showed the mRNA expression of BCL-2 and CDK2 was reduced, and the mRNA expression of caspase-3 was increased by roscovitine. Conclusion：Roscovitine could restrain proliferation and induce apoptosis in hepatic carcinoma cells. The mechanism of apoptosis depends on the activity of BCL-2 and caspase-3. CDK may play an important role on the proliferation and apoptosis in hepatic carcinoma cells.