Abstract: Most studies on rills are conducted under simulated rainfall condition. However, the study under natural rainfall condition is rare, especially under extreme storm condition. In this study, we investigated rill erosion under the rainstorm that occurred on 26 July, in Zizhou County, Shaanxi Province. The 16 investigation sites were in Qingshuigou small watershed involving 5 slope surfaces of slope farmland, including 3 straight slopes, 1 convex slope, and 1 shallow ditch terrain slope. For each investigation point, the size of the quadrats was set as 2 m×2 m, and 2-3 duplicates were set. Rill intensity, rill density and degree of rill dissection of each sample plot were measured to discuss the influence of slope position (distance from watershed), slope gradient and slope type on rill characteristics of slope farmland. The results showed that: rill erosion intensity, rill density and degree of rill dissection were 2 289-110 976 t/km2, 0.3-3.95 m/m2 and 0.002-0.441, respectively. The width of rills varied from 0.5 to 60 cm, with 51% rills ranging from 10 to 15 cm in width, and 93% rills was less than 20cm. The depth of the rill varied from 0.5 to 35 cm, with 69% of rills ranging from 0 to 5 cm, and 97% of the rill depth was less than 15cm. As the increase of distance from the watershed, rill erosion intensity increased, and rill erosion developed rapidly firstly and then slowed down. Between 17-58 m from the watershed, with the increase of distance, rills developed rapidly and the degree of fragmentation of the slope increased. After 58 m from the watershed, the development of rills slowed down and the degree of fragmentation of the slope weakened. The effect of slope gradient on the rill erosion varied among different slope positions. With the increase of slope gradient, in the upper part of the slope (20-40 m from the watershed), rill erosion intensity raised sharply, and slope fragmentation degree increased. With the increase of slope gradient, in the lower part of the slope (60-80 m from the watershed), rill erosion intensity increased slowly, and slope fragmentation degree weakened. In convex slope, the middle slope had the largest rill erosion intensity (10 292 t/km2), followed by the lower slope (8 141 t/km2) and the upper slope (no rill erosion but have surface erosion). With increase of the distance from watershed, rill density, degree of rill dissection and rill depth increased firstly and then decreased, while rill erosion intensity and rill depth increased. In the slope with shallow gully, the rill erosion of sloping farmland and abandoned farmland increased with the increase of the distance. However, the existence of abandoned farmland weakened the development of rill. In the straight slope, rill developed rapidly due to the larger slope gradient. Therefore， the straight slope had the largest rill erosion intensity, rill density and degree of rill dissection in the three slope types. This paper analyzes the erosion status and regularity of rills in slope farmland during this rainstorm, and discusses the influence of slope position, slope gradient and slope shape on rill erosion of slope surface, aim to provide reference for soil erosion control of sloping farmland on the Loess Plateau.