Abstract: HPV infection can lead to cervical lesions or cancer only if the infection of the high-risk type(s) of HPV persists for a long time. Although the HPV infection in cervix is common, most women with HPV infection can clear away HPV within a period of time. Some of them develop into the persistent HPV infection which is a high-risk factor of the high-grade cervical intraepithelial lesion. A small number of women with the persistent HPV infection develop into cervical cancer. The following factors have been found to increase the risk of the persistent HPV infection, such as age, multiple sexual partners, the infection of HPV plus other sexually transmitted viruses, multiple parturition（＞3 children）, hypoimmunity, and so on. The exact mechanism associated with clearance of HPV infection is not clarified. There is a lot of evidence to support the view that the HPV persistent infection is related to the immune status of host and the HPV-induced immune evasion. The role of immune system, including immune cells and cytokines, is important in viral clearance.

Key words: Papillomaviridae, Infection, Uterine cervical neoplasms, Genital neoplasms, female, Immune system