Abstract: Degradation behavior of tung oil as coating material in soil was studied.Tung oil was applied as coating material, using potted plant soil experiment method and the method of determinating mass loss in the soil was introduced. Results show that the speed of degradation of tung oil in soil was increased with the increase of temperature and soil moisture, the speed of degradation of tung oil as coating material in soil was decreased with increase of pH value of soil. Using the curve of C=C0e-kt for imitation. At soil moisture 20%,the half life of tung oil as coating material was 116d and at soil moisture 30%,the half life of tung oil as coating material was 52d. When temperature of soil increased from 15 to 35℃, degradation speed constant of tung oil as coating material was increased from 0.0036 to 0.008 9g/d. When the pH value of the soil increased from 4.0 to 6.0, degradation speed constant of tung oil as coating material was decreased 0.009 2g/d.