Objective: To evaluate the clinical effects of cone beam CT in the diagnosis of supernumerary teeth. Methods:81 patients with 106 supernumerary teeth examined by CBCT were retrospectively reviewed. The parameters included the number, area, size, spatial location, and growth direction of the supernumerary teeth, as well as their relationships with the adjacent teeth and organizations. Results: 106 supernumerary teeth were totally clearly discovered(including the number,area, size, spatial location, and growth direction of the supernumerary teeth, as well as their relationship with the adjacent teeth and organizations), and the rate of appearance was up to 100%. Conclusion: For treatment planning and practicing of supernumerary teeth, varied greatly accurate information were provided by cone beam CT.