The method of supplying geographical information system ARC/INFO to predict soi l erosion amount of watershed was probed. Based on the field survey

the geograp hical data base of Yuzigou small watershed was builded and the method of calcula ting the value of factors of USLE was studied. By the support of ARC/INFO ge ographical information system and integration of GIS and USLE

the soil erosion amount of Yuzigou small watershed was predicted. Results showed that the annua l average soil erosion amount was 3 893.38 t/km~2 and it belonged to middle deg ree erosion in Yuzigou small watershed;but the erosion amount of sloping land whose area accounted for 29.48% of the total area accounted for 81.98% of the total soil erosion amount of Yuzigou small watershed;the annual average soil er osion amount of sloping land was 10 826.54 t/km~2 and belonged to extremely st rong erosion. Results made clear that sloping land was the source of soil and w ater loss in Yuzigou small watershed and the key of harnessing soil and water l oss in watershed was that sloping land was rationally utilized.