Objecive To evaluate the clinic value of 320 rows spiral CT in diagnosis of rib fractures. Methods Eighty-six patients with rib fractures were examined by 320 rows spiral CT. After the scanning, rib three-dimensional reconstructions were carried out. The number of ribs fractures was compared with that demonstrated by X-ray and common spiral CT. Results All patients were examined successfully in 3~5 seconds. The images quality of ribs reconstructed by the new method was excellent and exquisite. Many linear fractures and depressed fractures and costobrachial fractures which were not displayed in the images reconstructed by common spiral CT were displayed. The difference was significant statistically. Conclusion Compared with common spiral CT, 320 rows spiral is superior, with faster scanning speed, lower radiological dose and better image quality, improving the diagnostic accuracy of rib fractures to some extent. Therefore, it is an advanced and reliable diagnostic tool for rib fractures.