Abstract: In order to study the mechanical mechanism of root fixation for slope protection in typical red loam mountain areas in southwest China, 4 kinds of landscape greening and slope protection plants from native plants （Rubus pectinellus, Osbeckia sikkimensis, Setaria palmifolia, Juncus effuses）were selected to carry on single root tensile test. Root mechanical properties and related influencing factors were analyzed comparatively．The results show that the root pull resistance of the four plant species was ranked as O. sikkimensis, J. effuses, R. pectinellus, S. palmifolia. The tensile strength increased and the tensile strength decreased with the increase of the root diameter. With the increase of root diameter, the lignin content and wood fiber ratio of root system in O. sikkimensis, S. palmifolia, J. effuses, while the cellulose content decreased. R. pectinellus changed on the contrary. The tensile properties of root systems of 4 plants are significantly correlated with cellulose and lignin content. O. sikkimensis, S. palmifolia, J. effuses root tensile force has a significant negative correlation with cellulose, and a significant positive correlation with lignin and wood fiber ratio. But their root tensile strength have a reverse change.The Relationship between root tensile properties and chemical composition of R. pectinellus are opposite to the other 3 plants. At the initial stage of root stress-strain curve, the elastic characteristics of linear relation are better, and the plastic material characteristics are presented when the load continues to increase. The maximum elongation of root system decreased with the increase of root diameter, the biggest is R. pectinellus. The mechanical properties of single root of 4 plants all meet the requirements of soil and water conservation plants.