A data set,which includes soil losses from field standard runoff plots established in red soil region during 229 rainfall events,was used to calibrate and validate the physically based soil erosion model(water erosion project,WEPP model).Meanwhile,sensitivity test and elastic coefficient analysis methods were applied to determine the major influencing factors of soil erosion and runoff on red soil slopelands.The results showed that erosion sediment yield is extremely sensitive to the input parameters including rainfall amount,intensity,rill erosion threshold,critical shear stress,slope length and gradient.Surface runoff is regulated strongly by the rainfall amounts,while is weakly sensitive to rainfall intensity,initial saturated hydraulic conductivity and effective hydraulic conductivity.In conclusion,all parameters aforementioned are the major controlling factors of soil erosion and runoff on red soil slopelands.