Objective To summarize the imaging characteristics and value of multislice CT (MSCT) in the diagnosis of acute appendicitis. Methods 56 patients with acute appendicitis confirmed by surgery and pathology were selected in this study, all patients underwent preoperative conventional whole abdominal MSCT, and MSCT imaging characteristics of acute appendicitis werer summarized. Results Of all the 56 patients, 23 cases showed periappendiceal inflammatory infiltration, and 33 cases showed no inflammatory infiltration and 6 cases showed abscess. The appendix of 4 cases located before and behind of ileocecum and behind of cecum respectively, 21 cases down of cecum and 23 cases down of ileum. MSCT can clearly show the appendix in 80.4% of the patients, and the mainly manifestation was swollen, and the average diameter was 12.1±4.6mm (6.1-21.6mm). Appendiceal stones were found in 9 cases which showed appendix expansion and effusion. The appendix can't clearly show in 11 patients by MSCT. 8.9% of the patients showed appendiceal perforation. The stones were replaced from the appendix to the abdominal cavity in the MSCT images, and periappendiceal gas could be seen. Conclusion MSCT can show appendix clearly. Acute appendicitis has special characteristics on MSCT, and it can be used as a routine preoperative examination for acute appendicitis.