When various kinds of meats were fried at around 200°C, the nicotinamide contents in deep-fried meats decreased compared with those in fresh meats. It was found that this was due to leaking the nicotinamide contained in meats into oil, but not the destruction of nicotinamide. The leak of nicotinamide into oil did not occur when the oil containing meat was kept at room temperature. When a test tube containing around 2 g piece of meat was added into 5 ml of corn oil and put into oil bath (200°C) for 5 min, 10-20 % of nicotinamide contained in meat was leaked into the oil.