Abstract: A two-year field experiment was carried out to evaluate degradation behavior and environmental safety of triadimefon WP in the soil/rape ecosystem and three simulant kinetic models were built up to simulate dynamic degradation of triadimefon in the soil/rape ecosystem and compared with each other.The results show that the fitting results of all the three kinetic models reached the level of statistic significance in relationship.However,the GM(1,1)and the retardation kinetic models were better than the other in simulating degradation of triadimefon in the soil/rape ecosystem.The half-life of triadimefon in the soil of 2003 and 2004 were 3.48 and 4.38 d,respectively,and in rape 1.98 and 3.78 d,respectively.The dynamic degradation of triadimefon in the soil/rape ecosystem was much influenced by the environmental temperature.