In the natural rainfall condition,this paper studied the characteristics of the output surface runoff of TN,TP,dissolved inorganic-N(NH+4-N,NO-3-N) and dissolved phosphorus(DP) in four different land types of the Jianshan river basin of Chengjiang,and analyzed the nutrition restriction and the eutrophication risk of the output runoff of four land types by utilizing the ratios of TN/TP,inorganic-N/DP,NO-3-N/DP,NH+4-N/DP.The results showed that the ability of preventing soil nutrients loss differed in the dif...