To study effects of roadside slope vegetation restoration on shear strength (τ) of and surface soil loss from the slopes, seven vegetation restoration models were adopted in in-situ shearing tests. It was found that vegetation root systems decreased in density with increasing soil depth, the root length density (RLD) in the 0~10 cm soil layer accounted for 34%~78% of the total RLDAnd the vegetation root magnitude was positively related to soil water content (SWC) showing a exponential function correlation. Shear strength of the surface soil layer (0~10 cm) was mainly affected by vegetation root systems and vegetation coverage and increased as a exponential function of RLD, root weight density (RWD) and vegetation cover (VC ). The controlling factors on τ varied with soil depth, and regression analysis showed RLD, RWD and VC had statistically significant effects on τ in the 10 cm soil depth. However, none of the predominant factors on τ were founded in the 30 cm soil depth, which was so defined as a transition layer and was the lowest shear strength τ as compared with the 10 cm and 50 cm soil depths. The influence of soil bulk density (ρ) andSWC got bigger on τ with soil depth, showing a positive linear relationship and a negative exponential function relationship, respectively in 50 cm soil depth.