Abstract: Considering soil erosion and nutrient loss, the effect of grass sowing by spraying for rock slope protection on anti-erosion was studied with simulating artificial rain. The relationship between the erosion loss and rain intensity, slope degree, amount of the seeding, and course of the grass development were analyzed quantitatively. The characteristics of the grass sowing by spraying for rock slope protection on anti-erosion were revealed.Results showed that the herbaceous vegetation could weaken kinetic energy of raindrops, and had a significant diffluent function during rainfall events to reduce effective precipitation on the slope. The erosion losses of soil and nutrients decreased with the increase of slope degree and amount of seeding, and increased with increasing rainfall intensity. There were remarkable functions between erosion losses and trial factors. The effects of the complex resisting rainfall exhibited remarkable temporal dynamic characteristics with grass development. The erosion losses of soil and nutrients kept a low level, even under higher rain intensity, which indicated that grass sowing by spraying for rock slope protection had good potential to resist rainfall.