[Background] China is one of the countries with most serious soil erosion in the world. In geomorphology and geology, soil erosion is the action of exogenic processes (such as water flow or wind) which remove soil and rock from one location on the earth's crust, then transport them to another location where they are deposited. Eroded sediment may be transported just a few millimeters, or thousands of kilometers. Soil erosion destroys the farmland, decreases agricultural productivity, descends the land fertility, leads to flood disaster and renders bad influence on the soil protection and land development, all because of loss of the nutrient-rich upper soil layers. The soil sediment on the upper soil layers will displace from the surface under the effect of rainfall splashing to other places. The soil sediment will also crush, disperse, and splash, which becomes one of the most important factors for mountain erosion. It occurs globally and becomes one of the most significant environmental problems. [Methods] In this study, taking the rocky mountain area of northern China as the research object, we conducted field experiment of artificial rainfall, used improved Morgan spattering plate and raindrop generator, and employed the stain method in combination with leaf area index to measure soil erosion rate under different conditions. [Results] 1) Splash erosion rate increased with the soil moisture content in the early stage and had a positive correlation with the kinetic energy of raindrops (R2 >0.96,P <0.05). 2) The amount of splash erosion had no linearly negative correlation with the vegetation coverage (R2 >0.99,P <0.05). There was lower splash erosion rate in the condition of higher intensity rainfall with higher vegetation coverage rate. 3) Leaf area changed the diameter of contacting raindrops and plant height changed the rainfall height. Then, plants redistributed the rainfall and changed the kinetic energy of raindrops. The smaller the leaf area index and height were, the stronger the blocking effect of splash erosion was. [Conclusions ] It is valuable to study mountain soil erosion factors for estimating soil erosion quantitatively. The process of rain splashing is short and it is complex to elucidate the single mechanism. Scientists take splashing and surface erosion as a sequential process, while it is not easy to advance the study deeper and more detailed. One raindrop has very little effect on soil erosion, and is difficult to measure the diameter of it; therefore, it is difficult to carry out quantitative research on it. Meanwhile, there are more indoor researches of slash erosion, compared with the outdoor utilization. And the theory of outdoor soil erosion needs to be popularized and applied in the field.