Abstract: In the loess regions loess landslide is one of the major geological disasters. Every year it results in a large number of casualties and destructions. It is found that the average shear stress on the sliding surface of these landslides is much smaller than their shear strength when the natural loess slope is slidded. One of the most important factors in the occurrence of these phenomena is the residual strength of soil. So the study on the residual strength of loess is of great significance. The test results show that the ring shear apparatus is the most realistic instrument to measure the residual strength of the soil, and the best way of measuring the residual strength of loess is single-stage shear. The ring shear test residual strength of Luochuan Q₂ loess is more realistic than the repeated shear. The initial structure of Luochuan Q₂ loess has few influences on the residual strength. The residual strength parameters (c_r, φ_r) of Luochuan Q₂ loess decrease with the increasing moisture content. The increase in the initial dry density causes the increase of the residual strength parameters of Luochuan Q₂ remolded loess. Luochuan remolded Q₂ residual remolded cohesion c_r decreases with the increasing shear rate, and the residual friction angle φ_r increases firstly and then decreases with the increasing shear rate.