Six dominant native plants in the dry and hot river valley of Dadu River in West Sichuan were selected in this study. The herbs selected were Bidens pilosa,Heteropogon contortus,Artemisia argyi,and Incarvillea arguta,and the shrubs were Barleria cristata and Indigofera tinctoria,to study the morphological characteristics,distribution properties,and changes in water content of their roots during the growth and senescence periods,and to calculate the differences in tensile strength (P) and thus cohesive strength (C_r) of their root systems,by means of tensile tests and to clarify the key factors influencing their variance. Results show: ①In terms of root distribution,the root area ratio (RAR) across all six plants tended to decrease with soil depth,with variations between growth and senescence periods. There is no significant difference was found in the mean values of RAR between shrubs and herbs.②In terms of root morphology,among the six plant,the roots of H. contortus had the favorable root length density and root number with the most stable water-holding capacity in different statues,which showed it had the best ability to survive in the dry season. ③The C_r values of the six dominant plants were significantly higher in the senescence period than those in the growth period,indicating that the soil fixation capacity of root system was stronger in the dry season than that in the rainy season. Both in the growing and senescence periods,the P-values and C_r values of H. contortus were significantly higher than those of the other plants. Pearson correlation analysis showed that root diameter and root water content were key determinants of tensile strength,with root diameter being the key factor influencing cohesive strength. Overall,H. contortus had the best soil-binding capacity and should be prioritized in the ecological restoration of the dry and hot river valley in western Sichuan.