Abstract: A non-local continuum model for strain-softening or damage of geo-materials with defects is derived based on nonlinear geometry field theory. Plastic strain or damage is represented by a non-local voriable in the model. Variational equations, numerical convolved integration algorithm of the model are also presented. The numerical simulations show that the model involved with the characteristic size, is able to analyze softening or damage of materials with defects as well as the deformation localization of geo-technical engineering excavation.