Abstract: In this paper,based on the mathematical theory of classical mechanics and Chen's theorem^[1],the variational method^[2] is used in the study of large deformation symmetrical elasticity problems.The generalized variational principles of potential energy and complementary energy,based on the instantaneous configuration are obtained,and the equivalence between the two principles is proved Besides,the generalized variational principles of dynamical problems based on the instantaneous configuration are also given.