Abstract: Objective: To investigate the expression and clinical significance of cytochrome P4501A1 ( CYP1A1) in squamous cell carcinoma( SCC) . Methods: The expressions of CYP1A1 in normal cervix tissue( 18 cases) ，cervical intraepithelial neoplasia( CIN)tissue( 33 cases) and SCC tissue ( 90 cases) were detected by immunohistochemicalstaining. The relationships between CYP1A1expression and clinicopathological features and prognosis of cervical cancer wereanalyzed. Results: The positive expression rate of CYP1A1 in SCC( 59. 7%) was higher than that in normal cervix(11. 1%) ( P ＜0. 05) . The positive expression rate of CYP1A1 in stage Ⅲ SCC( 69. 8%) was obviously higher than that in stageⅠ( 34. 8%) ( P ＜ 0. 05) . The positive expression rate of CYP1A1 in SCC with lymphnode metastases( 73. 6%) was higher than that in non-lymphnode metastases( 49. 3%) ( P ＜ 0. 05) . The expression differences of CYP1A1 in age，depth of invasion， stage and size of tumor had no statistic sigificance( P ＞ 0. 05) . Conclusions: The high expression of CYP1A1 may be associated with the occurence and development of cervical cancer.