Abstract： Objective To assess the high risk factors associated with the positive margin of conization in patients with cervical intraepithelial neoplasia (CIN). Methods From January 2000 to February 2008, 1699 consecutive patients with CIN undergoing conization was reviewed retrospectively in order to analyze the relationship between the positive margin of conization with clinical prognostic factors,such as patients age, disease grade, size of lesion, the procedure of excision and menopause. X<'2> tests was used to compare the different frequencies of factors in groups of positive and negative margin conization, then seven factors with positive margin were processed into unconditional logistic regression analysis. Results The rate of the positive margin in 1699 patients was 14.01% (238/1699). The mean age of patients with positive margins was (39±9 ) years old, while patients with negative margins was ( 39±8 ) years old, which didn't reach statistical difference(P>0.05). The rate of the positive margin was 8.63% in cold knife cone (CKC) and 18.66% in loop electrosurgical excision procedure (LEEP), which showed significant difference( P<0.01 ). Among 1699 patients, 90 patients were with CIN Ⅰ ,339 patients were with CIN Ⅱ ,1113 patients were with CIN Ⅲ [ including 972 with severe dysplasia and 141 with cancer in situ(CIS) ],87 patients were with cervical cancer stage Ⅰ al, 70 patients were with stage Ⅰ a2 or advanced stages. The rate of positive margin was 1.11% ( 1/90), 3.83% ( 13/339), 10.70% (104/972), 26.24% (37/141),35. 63% (31/87) and 74.29% (52/70),respectively. There was statistic difference among them, except CIN Ⅰ and CIN Ⅱ . When combined CIN Ⅰ with CIN Ⅱ , then compared with CIN Ⅲ, cervical cancer withⅠ al and Ⅰ a2, it also showed statistical difference (P<0.05 ) . The rate of positive margin in postmenopausal women was 21.54% (28/130), which was significantly higher than 13.38% (210/1569)in premenopausal women (P=0.010 ). The logistic regression analysis showed that the procedure of excision, grade of disease, size of lesion, surface of cervix, and menopause were high risk factors associated with the positive margin, the risk ratio were 5.147, 3.048, 1.271, 1.905 and 1.860, respectively.Conclusions High grade, the extent of CIN disease, LEEP and postmenopausal age are high-risk factors associated with positive margin in patients treated by conization. It should be warranted in those patients when designing conization treatment.