Abstract:Deformation reinforcement theory is developed and improved. The strict definition of structure failure and its logical description with set concept are presented. The criterion of structure stability based on plastic complementary energy and its variation is developed. The principle of minimum plastic complementary energy has been well proven. It is presented that the principle of minimum plastic complementary energy is the combination representation of structure equilibrium,coordination condition of deformation and constitutive relationship. The new idea that the structure global stability can be described by the relationship between the global degree of safety of structure and plastic complementary energy is presented;and then it is used in global stability evaluation of high arch dams. The results show that the deformation reinforcement theory provides uniform and practical theory framework and basis for high arch dams in evaluation of global stability,cracking problem of dam-heel,anchorage of dam-toe,reinforcement of faults and so on.