The research of the characteristics of rock and soil erosion was conducted on the dumpling platform and slope with the method of artificial rainfall and on the basis of analyzing the diameter-level of the selected spoil and residue particles in Jin'anqiao hydropower station

and the result showed that:(1) After removing the stones of which the particle diameter>2 cm

the percentage of spoil particle diameter>4 mm was 48.42%

which was 13.64 percent point more than the original landscape surface.In original landscape surface

the percentage of the particle diameter<0.25 mm was 15.81%

which was just 8.56% in the spoil particles.(2) In one rainfall process

the largest runoff was in dumpling platform

which is 2.27 times of the original grassland;and the smallest runoff was in the dumpling slope

which is 45.5% of the original grassland.(3) In one rainfall process

the initial sediment of both the dumpling platform and slope were lower than the original grassland of poor vegetation;when it archived stable sediment

the sediment of dumpling slope was close to the sediment of original grassland

and the sediment of the dumpling platform was much lower than the sediment of original grassland.(4) In one rainfall process

in the same period the grassland had the largest total sediment

followed by the dumpling platform

and the dumpling slope had the lowest sediment.(5) In the process of rock and soil erosion

the runoff amount and sediment yield had significant power function relations.