Abstract: Objective: To explore the CT features of perforated and non-perforated appendicitis,and evaluate its diagnostic value. Methods: 24 cases of appendicitis,selected and confirmed by operation and pathology,divided into 2 groups:perforated appendicitis group(10 cases)and non-perforated appendicitis group(14 cases).The CT signs were Analyzed and compared between the two groups.Results: Cellulitis around appendix,appendiceal wall discontinuity and periappendiceal pneumatosis are direct CT signs of perforated appendicitis,diagnosed with a high specificity(P<0.05).Abdominal abscess is confined expression of perforative appendicitis,and peritonitis is its diffuse sign.Indirect signs of CT include appendiceal thickening,wall thickening and strengthening,often combined with intracavitary effusions,bezoar,intestinal effusion,lymphadenopathy and adjacent bowel wall thickening.Conclusion: 64-MDCT is of high diagnostic value on perforated appendicitis.