Controlled Freezing-point Storage (CF Storage) is a new method of preserving foods in minus non-frozen temperature range. So, we tried to apply this method to entrails preservation and investigated the effect of controlled freezing-point storage of hearts on ventricular function in isolated perfused rat heart (male, Sprague dawley strain, in body about 300g weight). The hearts were perfused by working heart mode for 10min, and received infusion of cardioplegic solution which was followed by 4 hours of cardiac arrest at a myocardial temperature 4°C (4°C group) or minus non-frozen temperature (CF storage group). Then, the aerobic reperfusion by working heart mode was continued for an additional 30min. The recovery rate of cardiac output was 33.5% and 62.5% respectively of the preischemic value in 4°C group and CF storage group, which was statistically significant (p<0.01). ATP activity after 4 hours of cardiac arrest in 4°C group was significantly lower than that in CF storage group (p<0.05). These data suggest that CF storage of hearts might have a protective effect against an ischemic insult upon myocardial cell during hypothermic cardiac arrest.