Abstract: The characteristic IR absirption,thermal behavior of tung oil and its mixture with inorganic materials used in urea coating were investigated by means of FTIR and the DTA-TGA technology.The content of tung oil bolymer in coating materials was determined by residues percent of the coating materials after thermal degradation at 800℃.The results show that characteristic IR absorption of tung oil delonging to the doudle bond reduced or disappeared after being coated.After introducing inorganic materials into the tung oil,the position of Cxothermic peak of coating materials moved toward higher temperature.At the same coating percentage,for the urea coated with tung oil containing inorganic materials,the more the tung oil polymer content in coating materials,the better the ability of control release of the product.