Abstract: To study the effect of different nitrogen treatment on the microclimate,yield,and banded sclerotial blight of rice population,nitrogen fertilization at three different levels were applied on hybrid rice F You 498.The results showed that the yield was increased by the increase of nitrogen,but high nitrogen treatment did not significantly increase the yield;Seed setting rate and 1000-grain weight were decreased by increasing nitrogen,the effective panicles per plant was increased significantly (about 30%),which increased the yield by 19% rice increased;The permeability of the group (including the transmission of light and air permeability) significantly reduced by increasing nitrogen fertilizer,the temperature decreased while the humidity increased which deteriorated the microclimate and caused increasing banded sclerotial blight morbidity incidence.It is concluded that low nitrogen leads to low yield,high nitrogen causes deterioration of community ecological environment,so with a medium N application level at 150kg N/hm2,the output is not significantly reduced and community microclimate condition is better.Further study on the influence of different fertilizer treatment on community microclimate and the yield,is good for exploring a better way of achieving higher yield and reducing occurrence of pests and diseases.