[Objective] An extreme rainstorm was occurred in Yulin Region of Shaanxi Province in 26 July, 2017, resulting in very serious flood hazards and economic losses. The aims of this paper were to figure out the hazards of soil erosion in the rainstorm and provide basis for soil and water conservation and rainstorm hazards defenses.[Methods] Three small watersheds (Qingshuigou, Majiagou and Shejiagou) were selected as key investigation areas in Zizhou County (the devastated area in this rainstorm) in 2-6 August, 2017. Soil erosion of slope croplands, forest and grass lands after cropland abandoned, terraces, fields built by filling gullies, check dams and roads were investigated and analyzed.[Results] Rills developed evidently in slope croplands, and even small gullies developed in down slopes. While in forest and grass lands after cropland abandoned in 2000, sheet erosion was dominant and no obvious rills developed. In the new built terraces, the roads connecting two terraces, the field surfaces taking over the runoff from the roads, and the ridge in some sections were washed out seriously, and collapse occurred in the field walls. In fields built by filling gullies, crops and dam bodies were destroyed severely, the roads beside was eclipsed and the cutting walls were collapsed. Check dams were damaged more or less, but block runoff and sediment obviously. The main existing problems were wide spread steep slope farming, lacking storage and drainage systems in small watershed, deficiency in maintenance mechanism of soil and water conservation engineering, lower level of economic development, weak awareness of farmers in soil and water conservation.[Conclusion] Soil erosion under "7·26" extreme rainstorm was still severe, but it is slight in forest and grass lands after cropland abandoned. It suggested that soil and water conservation is still very important. Environmental protection measures should continue to be strengthened, and soil and water conservation, especially steep slope cropland abandonment should be increased in the fragile Loess Plateau of Northern Shaanxi Province. In the meanwhile, it is necessary to design and implement the storage, diversion and drainage network system in small watersheds.