According to the quality principle of soil particle size distribution and theories of soil fractal,characteristics of soil particle fractal under 3 typical coverage grasslands of the area with high-frequency debris flow were studied in Jiangjiagou ravine.The research showed that:Under different coverage grassland,soil particle size distribution had different fractal characteristics,its fractal dimension was between 2.520 8 to 2.669 1,and the order was low coverage grassland>middle coverage grassland>high co...