Objective：To investigate the clinical diagnosis and treatment of vaginal intraepithelial neoplasia（VAIN）. Methods：Fifteen cases of VAIN diagnosed and treated in the department of cervical diseases in the Maternal and Child Health Center of Chongqing from June 2006 to March 2012 were analyzed retrospectively. Results：The median age among all the patients were 50 years. Among 15 cases，12 cases（80.00%，12/15） were infected with HPV and 10 cases（66.67%，10/15） had hysterectomy for cervical disease before. Three months after the treatment，11 cases（73.33%，11/15） had complete response.Four cases had focus nidus sustained and were treated by CO2 laser therapy 3 to 6 months later，with complete response in 3 cases.However，one case developed to squamous cell carcinoma of the vagina one year later and was treated in the inpatient department. One year after the treatment，the negative transformation rate of HPV was 83.33%. Conclusions：The age of onset of VAIN is elder and VAIN is related with HPV infection，cervical intraepithelial neoplasia and cervical cancer. CO2 laser therapy can be used to treat VAIN and follow-up after the treatment should be taken for the risk of relapsing or developing into infiltrating carcinoma.