By analyzing the relationships between the cookery methods and the loss of Ascorbic acid included in fresh vegetables, t he best cookery method to minimize the loss of it has been studied. For being scald and parch, those scald only in the water and those parch the salad oil had fained the least loss of it, while those parch had gotten generally the less loss than those scald. And when the cooked vegetables were left alone in the air. Ascorbic acid included in those were decayed exponentially, and its half time was about two hours.