Aimed to reveal the mechanics of the soil reinforcement by root on the hedge of the sloping cultivated lands of purple soils in the Three Gorges Reservoir region, chosen three herbage hedge plants as the objects of this study. The root distribution and tensile strength of the three herbage hedge plants in the Three Gorges Reservoir region were compared. The results showed that the root biomass of Medicago sativa, Eulaliopsis binata and Pennisetum americanum × P. purpureum were （79.37±1.26）g/m2,（97.99±1.66）g/m2 and（71.76±1.96）g/m2, respectively. And the main root of Medicago sativa distributed in the 0 to 10 cm soil depth, the main root of Eulaliopsis binata distributed in the 10 to 20 cm soil depth and the main root of Pennisetum americanum × P. purpureum distributed deeper, in the 20 to 30 cm soil depth. The order of the average tensile resistance of the three herbage root were: Pennisetum americanum × P. purpureum (7.93 N)>Eulaliopsis binata (6.03 N)>Medicago sativa (5.40 N). There existed the power function relationship between the tensile resistance and root diameter, and there existed the highest correlation of Eulaliopsis binata roots. Meanwhile, the order of the tensile strength of the three herbage root were: Eulaliopsis binata (45.91 MPa)>Medicago sativa (19.68 MPa)> Pennisetum americanum × P. purpureum (15.28 MPa). There exited obviously significant difference of the tensile resistance and tensile strength among the three herbages roots（P<0.05）. The order of the soil anti-scouribility of the three herbage hedges were Eulaliopsis binata (85.28 L/(min·g))>Medicago sativa (69.47 L/(min·g))>Pennisetum americanum × P. purpureum (60.86 L/(min·g)), and there existed obviously significant difference among the soil anti-scouribility of the herbage hedges (P<0.05). While the value of the soil shear strength had the similar order, however, there did not existed obviously significant difference among the soil shear strength of the herbage hedges (P>0.05). The results showed that the Eulaliopsis binata hedge had the better soil reinforcement and soil conservation in this region. And the herbage reinforced the hedges was a new idea for the sloping cultivated lands harnessing in the Three Gorges Reservoir region.