Objective To investigate the value of CT in diagnosis of acuteppendicitis. Methods Acute appendicitis was confirmed by pathology in 30 cases after the operation. CT features of 30 acute appendicitis were analyzed and compared with the surgery and pathological results retrospectively. Results Among of 30 acute appendicitis,20 cases were simple appendicitis,6 cases were acute suppurative appendicitis and 4 cases were appendiceal abscess. 20 cases simple appendicitis showed the appendix enlarged in diameter,with wall thickening in CT imaging. 6 cases acute suppurative appendicitis showed the appendix enlarged in diameter,with wall thickening and periappendiceal inflammation in CT imaging. 4 cases appendiceal abscess showed inflammatory tumors with asymmetrical attenuation in ileocecal region and complicating fluid collection in right iliac fossa and cavity of pelvis in CT imaging. In 4 cases appendiceal abscess,2 cases complicated small intestine obstruction. 7 cases appendiceal fecalith were found in 30 acute appendicitis. Conclusion CT scanning can illustrate feature of acute appendicitis and make correct diagnosis,and can provide important information for clinician.