Abstract: Objective To study the effect of small interfering RNA (siRNA) of human papillomavirus (HPV) 18 E6 gene on apoptosis in HPV-related cervical HeLa cell line. Methods siRNA targeting HPV18 E6 mRNA were designed and generated by PCR amplification. The PCR products containing U6 promoter and the siRNA sequence were then transfected into HeLa cells via LipofectamineTM2000. At different times after transfection, cell viability was determined by MTT assay. Apoptosis was detected by morphological observation and flow cytometry analysis. The expression levels of HPV18 E6 mRNA was assayed by RT-PCR. Results The cell growth and viability of siRNA transfected group were significantly inhibited（P＜0.05）. There were obvious morphological changes in HeLa cells after transfection of siRNA under optical microscopy and the apoptosis rate at 72h was 55.8%. HPV18 E6 mRNA expression in the cells of the interference group at 24、48 and 72h after transfection were significantly reduced by about 57%、78% and 40% respectively, as compared with that of the negative and blank control groups, whereas the latter two groups had similar expression levels. Conclusions Interference with siRNA against HPV18 E6 gene can effectively inhibit the specific gene expression which may play significant role of the induction of apoptosis of the corresponding Hela cells.