〔Abstract〕 Objective To explore the clinical value of computed tomography colonography(CTC) based colonic imaging features evaluating incomplete colonoscopy. Methods 71 patients who underwent both CTC and colonoscopy were retrospectively collected and divided into complete group(n=30) and incomplete group(n=41) according to whether the colonoscopy reached the ileocecal region. The clinical factors and imaging features related to incomplete colonoscopy were analyzed, and the value of imaging features in predicting incomplete colonoscopy was evaluated. Results Compared with the complete group, the incomplete group had a higher age(P<0.001), higher sigmoid parietal height(P<0.001),longer colon length(P<0.001), longer abdominal circumference in supine position(P=0.005) and more tortuosity(P=0.003). The area under the ROC curve of sigmoid apex height, colon length, supine abdominal circumference, tortuosity and combined with these featuress were 0.741, 0.795, 0.685, 0.704, 0.850, respectively. Conclusion Age, high sigmoid length and abdominal circumferences in supine position are associated with incomplete colonoscopy, and the combination of multiple imaging features can better predict whether the colonoscopy can be completed.