Purpose: Exostosis osteochondroma is usually resected with the whole condyle even part of it is not involved.This study was to report the effect of using digital template in the assistant of resection while protecting the uninvolved condyle.Methods: We used computer-aided design (CAD) technique in the assistant of making preoperative plan of a patient with giant condylar osteochondroma of exogenous type, including determining the boundary between the tumor and the articular surface of condyle, and designing the virtual tumor resection plane, surgical approach and remove-out path of the tumor.The digital osteotomy template was made by rapid prototyping (RP) technique based on the preoperative plan.Postoperative CT scan was performed and merged with the preoperative CT by the Proplan 1.3 system to evaluate the accuracy of surgical resection with the guide of digital template.