Objective To compare the value of MRI and CT in the diagnosis of rectal cancer staging.Methods This study performed a retrospective survey and analyzed the data of 98 cases of preoperative imaging,including MRI and CT images,and the results were compared with the postoperative pathological examination,to evaluate the value of preoperative diagnosis of the two methods.Results The diagnostic accuracy of MRI in T1,T2,T3 (92.1％,74.4％,80.0％) were higher than those of CT (79.4％,29.2％),the diagnostic accuracy of MRI in N0,N1,N2 on (77.6％,83.3％) were higher than those of CT(49.0％,46.2％,30.0％),the difference was statistically significant (x2 =9.55,P ＜ 0.05).In the lymph node metastasis,MRI misdiagnosis rate (20.0％,3/15) was slightly lower than that of CT (26.7％,4/15).Conclusion For patients with rectal cancer,MRI in the diagnosis of T1-T3,N staging were is better than CT,it is an ideal preoperative diagnosis method,it is and is worthy of clinical application for reference.