Abstract: The mechanical mechanism of soil-reinforcement by roots had been studied by the tests for the pull-resistance of roots of vegetation which were in different recovery stages in Xinping ecological restoration region. Results showed that this improved method was an effective method which was able to conduct the experiment on the slope of mountainous area and study the root’s mechanics function of plant communities which were composed of different species. The relationship between load and displacement in the process of root’s level pull-resistance was obtained quantitatively, and the F-S curve was drawn. The F-S curves showed that all kinds of roots for different plant quadrats had different tensile properties, but they all passed through the elastic deformation stage, the plastic deformation stage and the strengthened stage. These roots played an important part in soil-reinforcement. Besides, with the development of ecological restoration process, the ecosystem’s soil-reinforcement ability was enhanced.