Unsaturated loess is a typical structural soil. The triaxial shearing tests for four kinds water content intact unsaturated loess and remolded unsaturated loess under three kinds of consolidtation pressures were carried out. Based on the tests and the concept of geo-binary medium model

the stress share ratio as a quantitative parameter has been proposed to study the structure of unsaturated loess. The effect of consolidation pressure and water content are analyzed and the stress share ratio is described by a mathematic formula. Results show that the structure of loess is mainly affected by consolidation pressure and water content. The stress share ratio increases linearly then decreases exponentially with the increment of strain. Further the stress share ratio was applied to the constitutive model of intact unsaturated loess