Objective To observe the clinical efficacy of anterior fusion with the internal fixation system in the treatment for unstable Hangman fractures. Methods 19 cases with unstable Hangman fracture were involved in this study, who all underwent anterior cervical discectomy and fusion. Results All patients were followed up for 10~66 months, average 37 months. No spinal cord injury，vertebral artery injury or cerebrospinal fluid leakage occurred, complications such as plate-screw internal fixation of fracture failure did not occur. 15 patients were cured with bony union and restoration of cervical curvature, fracture line in 4 cases could be seen but no delayed symptoms of spinal cord injury. 5 cases which have cervical spinal cord injury spinal cord function was improved from 1～2 grade in 4 cases. Conclusions Anterior cervical fusion with internal plate fixation could be used for treating unstable Hangman fracture patients with type Ⅱ or type ⅡA.