Shear strength properties of slip soils are important for landslide research and control design. Based on the review of presently available literature

especially some typical investigations

the paper summarizes their major research advances

covering areas

methods and achievements. The five feature strengths

i.e. peak shear strength

residual strength

full softened strength

mobilized strength and long-term strength

and their related microstructure characteristics are the basic research elements; the field and laboratory tests are the basic research methods

while back analysis and theoretical analysis are secondary; achievements are reached mainly in the area of shear-induced microstructure characteristics

feature strengths and their relations. Residual strength research is discussed in detail

especially its influencing factors and estimations. Finally

the paper indicates some aspects to be strengthened

including special slip soils

e.g. slip soils with gravel

development of new testing and analysis method and the proper application of back analysis method

etc..