Quantitative analysis of slope rill morphological characteristics is the basis of rill erosion research. The artificial rainfall simulation tests under the combinations of three rainfall intensities (30, 60 and 90 mm/h) and five slopes (2°, 5°, 10°, 15° and 20°) were conducted, and the effects of rainfall intensity and slope on rill morphology and its spatial change characteristics of saturated purple soil slope were quantitatively studied. The results showed that the average width, depth and ratio of width to depth of rill on the saturated purple soil slope was 3.44~9.64 cm, 1.01~8.14 cm and 1.18~3.87, respectively. The width and depth of rill increased first and then decreased from top to bottom along the slope surface, and the ratio of rill width to depth of rill along the slope surface followed the order of upper