Currently,the activated sludge models in which the ASM of IWA(International Water Association) have been widely used in the design rebuild and operation of the waste water treatment plant and the development of new technic. By analyzed the composition of water and modified the paramters of ASM2, we use ASM2 to simulate the removing of COD nitrogen and phospherus in the sprial up-flow reacto(SUFR) system. The result indicates that the simulation value tally the fact on the whole. It shows that the ASM2 can primely reflect the change of COD nitrogen and phospherus in SUFR system. When the operational paramters have been changed, the model will be an effective forecast platform.