In order to establish methods of potato processing for mixed cooking with rice as main dish, the sire and shape of potato granules and favorahle ratio of potato granules to rice for cooking were studied preliminary. As the results cylindrical shaped potato granule of around 6㎜ in diameter and 10∼13㎜ in length are more favorable than rectiangular shape for mixed cooking according to panel test. Mixed cooking of 30% of treated potato granules with rice is the most favorable in the paint of palatability.