Abstract: ob＜x＞jective To investigate the MRI features of perianal Crohn’s disease in patients with and without proctitis. Methods 57 patients with perianal Crohn’s disease in Affiliated Hospital of Yangzhou University and Affiliated Hospital of Nanjing University of Chinese Medicine from September 2017 to July 2021 were analyzed retrospectively, including 42 males and 15 females, aged from 21 to 56 years, with an average age of 29 years. 30 cases of perianal Crohn’s patients with rectal inflammation were set as proctitis group, and 27 cases of perianal Crohn’s patients without rectal inflammation were set as non proctitis group. The following indexes were analyzed by MRI images: The thickness of rectal wall; Apparent diffusion coefficient (ADC) of rectal wall; T2 signal of rectal wall; Whether the position of fistula opening is high (the position of fistula opening in rectal wall is regarded as high); Supralevatoric fistula; Supralevatoric abscess. Independent sample t-test (normal distribution) or nonparametric test (skew distribution) was used for comparison between measurement data groups；Count data were described as the percentage, and comparisons between groups were performed by using the chi-square test or Fisher’s exact test.Results The mean rectal wall thickness in proctitis and non proctitis groups were (8.4±2.1)mm and (5.5±1.6)mm respectively, and the mean ADC was 1.09×10-3 mm2/s and 1.36×10-3mm2/s respectively; In proctitis group, there were 7, 14 and 9 cases with obvious-moderate-slight increase of T2 signal in rectal wall, and in nonproctitis group, there were 2, 7 and 20 cases. The incidence of high fistula opening in proctitis group and non proctitis group were 43.3% and 18.5%. The incidence of supralevatoric fistula was 23.3% and 7.4%, and the incidence of supralevatoric abscess was 13.3% and 0%. There were significant differences in rectal wall thickness, ADC value, T2 signal of rectal wall and the incidence of high fistula opening between proctitis group and non rectal group (P<0.05), but there were no significant differences in the incidence of supralevatoric fistula and abscess(P>0.05). Conclusion Compared with perianal Crohn’s disease without proctitis, MRI findings of patients with perianal Crohn’s disease with proctitis have certain characteristics.