On the basis of previous works this paper attempts to apply the theory of plate-tectonics as suggested from data of oceanic crust to the study of the geology of continental crust. The presence of "Yangze old plate" is inferred from the study of rock formations; from the structural deformations produced in several diastrophic periods the direction of force affecting the South China plate is studied and according to the space-time relationships the formation and evol-ution of continental crust in South China are also disclosed. The evolution of the present "South China plate" is thus briefly sketched.The "Yangze old plate" formed during the Jinning-Chengjiang period in the southern part of China (south of Mts Qilianshan-Qinling) acted, since the beginning of the Paleozoic as a continental core and kept on expanding along its east and west margins from the Caledonian to the Himalayan periods until it became at last the "South China plate".