Abstract: Post-orogenic extension had occurred in I ate Paleozoic at northern margin of the North China Platform. The orogeny occurred in late Devonian-Early Carboniferous and foreland basin is formed and accumulated littora1-epicontinental sea facies molasse deposition and formed a lot of synorogenic granites. Intracontinental extension tectonics process occurred in Middle Carboniferous-Early Permian which formed a lot of volcanic rocks. The alkalian content of volconic rocks is high (Na2O> K2O) and the differentiation index of volcanic rocks is characterized by bimodality. Composition and texture maturity of clastic rocks indicates that extensional process occurred from Middle Carboniferous to Early Permian.