Storm rainfall is a key and dynamic factor to erode soil in the Loess Plateau. Usually

serious soil erosion on the Loess Plateau is caused by a few storm rainfall.Hence

studying storm rainfall standard and further making

storm rainfall division in the Loess Plateau are of great significance for soil and water conservation planning in the Loess Plateau. Though several storm rainfall standards in the Loess Plateau were made before，it cannot utterly meet the needs of soil ail witer conservation works fully because they mainly paid attention to flood prevention and scarcely to soil erosion.In this paper

we develop the storm rainfall standard in the consideration of roil erosion

that is

soil erosion storm rainfall standard in the Loess Plateau Fby simulated rainfall. Here

storm rainfall is defined as the rainfall because rof which runoff appears on the slopes

and storm rainfall is subdivided into-common storm rainfall which cannot cause rills on the slopes and heavy storm rainfall which can cause rills. Experiments were made on the plot(5 x 1.5 = 7. 5m E ) which unif orm loess parent material

20 degree of slope and no vegetation by lateral sprinkling rainmaker. Based on statistic analysis and energy conversion of experimeritai result

soil erosion storm rainfall standard for the natural rainfall in the Loess Plateau is made (tab

4)