Objective：To investigate the risk factors for failure in transvaginal debridement of pregnancy tissue at cesarean scar with or without uterus repair in the treatment of type Ⅱ cesarean scar pregnancy（CSP） using a retrospective analysis，and to provide a refer－ence for clinical treatment. Methods：A total of 98 patients who were diagnosed with type Ⅱ CSP and underwent vaginal surgery in our hospital from April 2016 to March 2018 were enrolled. Among these patients，82 underwent successful transvaginal debridement of pregnancy tissue at cesarean scar and uterus repair，14 underwent transvaginal debridement alone，and 2 were converted to laparoscopy due to surgical difficulties. The former 82 patients were enrolled as successful vaginal surgery group，and the remaining 16 patients were enrolled as treatment failure group. The chi-square test，the t-test，and the rank sum test were used for comparison of the gener－al status between the two groups，and univariate and multivariate logistic regression analyses were used to screen out the high-risk factors for vaginal surgery in the treatment of type Ⅱ CSP. The receiver operating characteristic（ROC） curve was plotted to determine cut-off values. Results：There were no significant differences between the two groups in age，number of days of menopause，number of times of cesarean section，time from the last cesarean section to this pregnancy，diameter of pregnancy sac，preopera－tive HCG，scar thickness，whether methotrexate pretreatment was performed before surgery，and intraoperative bleeding（P>0.05）. There were significant differences between the two groups in the distance from scar to external cervical orifice（3.364±0.802 vs. 4.050±0.701，P<0.05） and length of hospital stay（5.560±1.813 days vs 6.560±1.711 days，P<0.05）. The univariate and multivariate logistic regression analyses showed that distance from scar to external cervical orifice was a high-risk factor for failure in vaginal surgery for the treatment of type Ⅱ CSP（univariate：odds ratio[OR]=0.289，95% confidence interval[CI]：0.126-0.659，P=0.003；multivariate：OR=0.177，95%CI＝0.051 to 0.611，P=0.006）. The ROC curve showed that distance from scar to external cervical orifice had a sensitivity of 87.3%，a specificity of 50.0%，and an accuracy of 73.7% at the optimal cut-off value of 4.25 cm. Conclusion：Vaginal surgery is a relatively safe method for the treatment of type Ⅱ CSP，and patients suitable for this method should be selected. When the distance from scar to external cervical orifice is greater than 4.25 cm，patients should be fully informed of risks before surgery，and preparations for laparoscopy or interventional therapy should be made，or other treatment methods should be adopted.