Cervical cancer the most frequent neoplasm and the fifth mortality rate of malignancies of the women in the world. It results in about 1,000 women in Taiwan and about 200,000 women worldwide dying of cervical cancer each year. Human papilloma viruses (HPV) have been consistently implicated in causing cervical cancer especially those high-risk types (HPV 16,18,31,45) have been strongly associated with cervical cancer. Around 50-80 % of women are infected by HPV within their whole lives. However, only 1% of HPV-infected women have cervical cancer eventually. Seventy and 91% of HPV infection could be cleaned up by host immune responses within 1 and 2 years later. It shows that host immunity plays an important role in the progression, persistence, or regression of HPV infection.