Abstract: Based on the concept of geo-binary medium model,a strength criterion for structured soils was proposed.The soil engineering characteristics of structured soils and reconstituted soils were different in many aspects,including the strength properties.The strength criteria currently established were formulated on the basis of the properties of reconstituted or reconstituted soils,which could not reflect the influence of soil structures(bonding and fabric) on the properties of structured soils.After the strength behavior and mechanisms of structured soils were analyzed from many strength tests of the structured soils,the strength criterion for structured soils was established based on the concept of geo-binary medium model considering the fracture mechanism of geomaterials.The parameter of shear resistance contribution ratio was introduced and the determination of the parameters was also presented.By comparisons of predictions with experimental data of structured soils conducted under true triaxial and conventional triaxial stress conditions,it was demonstrated that the new strength criterion could provide satisfactory qualitative and quantitative modeling of strength features of structured soils.