[Objective] The soil reinforcement effect of root systems of Leucaena leucocephala and Coriaria sinnica was studied in Jiangjia gully, Dongchuan District, Kunming City, Yunnan Province in order to provide a theoretical basis and data support for the application of local biological and engineering methods to utilize the control benefit of debris flow.[Methods] The distribution characteristics of root systems were identified using the root digging method, the root tensile characteristics were analyzed with the root tensile test, and the added value of the root systems of the two plant species to the soil shear strength was calculated using the Wu-Waldron model (RWM).[Results] ① The root area ratio of both L. leucocephala and C. sinnica decreased with an increase in soil depth. ② The root configurations of L. leucocephala and C. sinnica were vertical type and transverse type, respectively. ③ The relationship between the tensile strength and root diameter of C. sinnica roots was a decreasing logarithmic function, whereas there was no obvious regularity between tensile strength and root diameter for L. leucocephala roots. ④ The added value of the shearing strength of both L. leucocephala and C. sinnica roots decreased with an increase in soil depth. The depth of soil reinforcement of L. leucocephala and C. sinnica roots was approximately 1.4 m and 0.6 m, respectively.[Conclusion] Both root systems of L. leucocephala and C. sinnica played a significant role in soil fixation. Because the root architecture, soil reinforcement depth, and soil reinforcement technique of these two plants were different, utilizing these two species together can improve slope stability and soil anti-scourability.