Recently, early defibrillation and cardiopulmonary resuscitation (CPR) for sudden onset of cardiac arrest are advancing, however, survival rate is still very low in the world. Furthermore, post-cardiac arrest brain injury is a common cause of morbidity and mortality after successful resuscitation which is urgent issue to be solved. Therapeutic hypothermia is part of a standardized treatment strategy for comatose survivors of cardiac arrest in the metabolic phase usually about 15 minutes after cardiac arrest. However, the evidences of the efficacy of therapeutic hypothermia are still few. The optimal candidates, temperature, the timing of initiation, the therapeutic windows and the rate for rewarming have not been defined clinically and should be established. The purpose of this research is the improvement in the outcomes for patients with coma after resuscitation from out-of-hospital cardiac arrest using therapeutic hypothermia established from the analysis of multicenter registry data.