The Loess Plateau is one of the areas with the most serious soil erosion and ecological environment problems in China. Vegetation restoration is an important measure to prevent and control soil and water loss. The plant vertical cover structure includes aboveground canopy, surface litter, and underground root system. Each component has a different role in soil and water conservation. It is the basic unit to study the relationship between vegetation and soil erosion. At present, the research on the effects of different components of plant vertical cover structure on soil erosion in loess hilly areas is mainly based on artificial rainfall, and there is a lack of systematic research on the effects of different plants vertical cover structure on runoff, sediment and infiltration under the condition of natural rainfall. The research objects of this study were the typical grass (Andropogon yunnanensis), sub-shrub (Artemisia sacrorum) and shrub (Spiraea pubescens) in loess hilly areas. Each plant was treated with three different vertical cover structure compositions (e.g., intact condition, removing litter and only roots) and bare land control treatment. The runoff, sediment yield and infiltration of rainfall events from 2015 to 2016 were observed. The runoff and soil loss reduction and relative contributions of different vertical cover structures were analyzed. The results showed that the three types of plants had great runoff reduction (45.9%-73.2%), soil loss reduction (87.5%-94.6%), and increased infiltration (4.7%-10.8%). The runoff reduction of shrub (73.2%) was significantly higher than that of grass (45.9%) and sub-shrub (63.5%). However, there was no significant difference in soil loss reduction among the three plants. The canopy had the greatest effect of reducing runoff, with a contribution rate close to half (48%-50%). The contribution of grass litter to runoff reduction was basically the same as that of the roots, while the contribution of sub-shrub and shrub litter was slightly higher than that of the roots. The contribution of canopy, litter and roots to soil loss reduction was basically same (36%, 30% and 34%). In specific, the roots of grass had a greater effect on controlling erosion, and the contribution to soil loss reduction rate reached 39%, while the contribution of sub-shrub and shrub canopy to soil loss reduction rate was slightly higher than that of litter and roots. The study shows that the canopy is an important factor in runoff reduction, while the canopy, litter and roots all play an important role in reducing soil loss. The differences in the ability of the vertical cover structure to reduce runoff and soil loss among different plants mainly related to plant functional traits. The above results will provide a scientific basis for vegetation restoration and soil erosion control on slopes in the loess hilly region.