[Objective] We aimed to study the characteristics of soil erosion and non-point pollutants-nitrogen and phosphorus in Danjiangkou reservoir area

and to provide theoretical basis for the establishment of agricultural non point source pollution model. [Methods] Through rainfall simulation experiments

we analyzed factors affecting soil and water loss and soil nutrients

including total nitrogen(TN)

NH4-N

NO3-N

total phosphorus(TP)

available phosphorus(AP)

from purple soil

such as slope gradient and fertilizer measures. [Results] (1) The average infiltration rate and the initial runoff time decreased

however the total amount of runoff and sediment increased with the creasing slope. (2) The concentration of TN

NO3-N

TP and AP in sediments decreased with the increasing slope when they were under the same treatment. The concentration of NH4-N in runoff decreased under the condition of no nitrogen

and increased under nitrogen treatment. (3) The loss of TN was stable after the first reducing trend

the loss of NH4-N under various fertilizer treatments showed a wave-like change

the loss of NO3-N gradually decreased and flatten out at last under nitrogen treatment

but had almost no change under the condition of no nitrogen along with the rainfall time under the condition of the same grade. [Conclusion] The NO3-N was mainly lost with runoff

which was 8 to 11 times of the loss with sediment. NH4-N loss was mainly caused by the sediment erosion

which was 1 to 17 of times the loss caused by runoff erosion. The total loss of nitrogen was summary of the loss in runoff and sediment. The main way of the loss of AP and TP were lost by sediment

which were 1 000 to 6 200 times and 1 to 3 times of that by runoff erosion

respectively.