Abstract: The mechanical response of structured soil has obvious damage effects. According to the theory of complex for geotechnical materials, structured soil can be considered as the composite material constituted by the structured phase and the damaded phase. Structured soil damage process should be the deformation energy in the structural phase transiting to the dissipated energy of damage, and damage dissipative of phase change induce structural phase change to the damage phase. Viewing from a cross-section in any direction, damage resulting in the surface of structured phase into damage one. Based on this understanding, the damage variable is linking to cross-section areas of structured phase and damage phase is consistent with that of the damage variable in the classical continuum damage mechanics. The external force damage power is defined as damage dissipation energy, and introduced into the soil energy balance equation. For a typical unit of energy, a damage evolution equation is derived based on the energy consumption under the conditions of structural damage, and the determination method is provided for the model parameters. Finally, the comparison of test results and that of this model show that the proposed model can reflect the evolution of soil damage properly.