[Objective] The objective is to investigate the losses of nitrogen and phosphorus in typical weathered granite parent material soil under erosive environment

and to discuss the contribution rates of nitrogen and phosphorus losses in slope runoff and interflow.[Methods] Slope gradients(8°

25°) and rainfall intensities (30

60

90

120

150 mm/h) were selected as the variable factors for artificially simulated rainfall experiments

the study revealed the distributions of nitrogen and phosphorus losses in slope runoff and interflow based on mass concentration and runoff volume analyses.[Results] ① In the heavily eroded sloping fields

soil structure was instable; the soil was highly permeable

so the proportion of nitrogen and phosphorus loss in interflow was very large. The amount of TN loss in the interflow accounted for more than 90% of the total loss

and TP loss was slightly lower. ② The loss of TN with runoff was much greater than the loss of TP. TN in the slope runoff can reach 160 times higher than the total loss of TP. ③ The effect of rainfall intensities on the losses of nitrogen and phosphorus were greater than that of slope gradients; and the effect of runoff volume was greater than that of mass concentration. ④ There were two transitions in the effect of rainfall intensity on nitrogen and phosphorus loss

the first one was near 60 mm/h rainfall intensity

at which full-stored Horton runoff begin tranited to one dunne

and the second was 90 mm/min

from that on

the rain intensity became erosive.[Conclusion] Strong erosion affects both the loss of soil nutrients and the ratio of loss pathways. The losses of nitrogen and phosphorus in the interflow contribute a large proportion to the total ones

which inveitablly affects the quality of groundwater. Strengthening the prevention and control of soil erosion on sloping fields in rock formations soil is the basis for the control of non-point source pollution of surface water and groundwater

and it is essential to reduce soil nutrient loss.