In Tai Lake watershed the crop yield increasing has been more and more depended upon the increasing application of chemical fertilizer.The nitrogen utilization efficiency(NUE) has greatly decreased,and the water in Tai Lake is more and more polluted.We studied the rice yield,nitrogen utilization efficiency,nitrogen leaching amount at different level of nitrogen fertilizer using in paddy rice field.The results show that with the Coase Theory of Environmental Economics and the Marginal Revenue Analysis Theory...