Abstract: Objective: To study the apoptosis by cisplatin on cervical cancer cell line HeLa and its mechanism of action in vitro. Methods: The cell-growth inhibition of cisplatin on HeLa cells was analyzed by MTT assay; the cell apoptosis was measured with cytometry and Hoechst 33258 when treated with cisplatin. The effect of cisplatin on transcription of E6 was analyzed using RT-PCR. The expressions of the protein E6, p53, p21, Bax and Bcl-2 were studied by western blot. Results: Cisplatin inhibited proliferation in a time- and dose-dependant manner. The sub-G₁ peak detected by flowcytometry showed a significant difference between the experimental group and the controls. The effect of Hoechst 33258 showed the apoptosis induced by cisplatin, RT-PCR showed transcription level of HPV E6 decreased gradually after administering cisplatin and the Western Blot indicated the level of expression of the protein HPV E6 decreased gradually after treatment by cisplatin on HeLa cells. The level of expression of the proteins p53, p21 and Bax increased gradually, while no effect on the expression of the protein Bcl-2 was found. Conclusion: Cisplatin can induce apoptosis of HeLa cells to kill the tumor cells by suppressing the expression of HPV E6 to restore the function of p53.