Objective To explore the relationship between ileocolonic lesions and perianal fistulas of Crohn's disease as sessed by CT enterography (CTE).Methods Totally 28 patients with initial diagnosis of active ileocolonic lesions of Crohn 's disease were collected,16 with perianal fistula and 11 without perianal fistulas.All patients underwent CTE and pelvic MRI.Total number of lesions,minimum length between every two lesions in colon wall and maximum length of colonic le sions were calculated.The rank sum test was performed respectively.Results Lesions of 14 patients (14/16,87.50％) in perianal fistulas group located in left colon or rectum,while lesions of 6 patients (6/12,50.00 ％) in non-perianal fistulas group located in left colon or rectum,the difference was statistically significant (Z=-2.135,P＜0.05).The mean number of lesions in patients with perianal fistulas was 3.06,while in patients without perianal fistulas was 2.91,there was no statistical difference (P＞0.05).The maximum length of colonic lesions in patients with perianal fistulas was (12.79± 8.30)cm,while in patients without perianal fistulas was (7.04± 3.09)cm,and there was no statistical difference(P＞ 0.05).The minimum length hetween every two lesions in patients with perianal fistulas was (5.23±2.98)cm,while in pa tients without perianal fistulas was (8.44 ± 2.87) cm,the difference was statistically significant (Z =-2.095,P＜ 0.05).Conclusion Crohn's disease complicated with perianal fistulas has relationship with lesion location and smaller length intervals between two lesions in colon wall,and has no relationship with total number of lesions and maximum length of colon lesions.