There is about 80 percent heat passing from roof into storehouse. A contrastive test is carried through on improvement of the heat insulation of grain storehouse’s roof, adopting aluminum foil with large reflection coefficient and low radiant coefficient and hard-forth urethane with low heat transfer coefficient. The result indicates both of the two materials have a better effect, especially combination with them. It can not only decrease 4～5°C in storehouses and 3～4°C in grains at the highest temperature, but also delay aging of grain. However the aluminum foil will crack in more than two years. It shows superiority both in effect and natural life, according to the test which is conducted using sun proof paint as substitute for aluminum foil. The conclusion is that it is a preferable technical measure of improvement of the heat insulation to sprinkle paint of heat insulation and sun proof and forth urethane on roof of storehouses built.