Abstract:The disease investigation of tall fescue turfgrass was studied under different nitrogen and potassium application treatments in the field.The results showed that the potassium application rate and the interaction of nitrogen and potasssium had not significant effect on the degree of disease occurring,the different nitrogen application treatments mainly effected the rate of disease spreading as it says the higher rates of nitrogen appliction in the experiment,the more spreading of the disease,but the recovery speed was slowly.