Abstract: Seismic data obtained in the folded zone in Eastern Sichuan Basin show that sediments cover in this area consist of several separated structral sequences. Some plastic formations with certain thickness act as separators. Among them, the Permo-Carboniferous carbonate sequence is one of most interest objects in hydrocarbon exploration. In cosespondence to a simple Jurassic surface fold anticline, the Permo-Carboniferous structure is generally decomposed to several falted blocks with different features. It may be summarized to a structural mede with five-blocks generally, namely, back steep block; up thrust block; front steep block; sag block and counter thrust block in sequence. The complex data of a large number of wells indicate that hydrocarbon pools may be found both on up thrust and counter thrust blocks. Herein, the gas pools in Carboniferous dolomite are structural and fault traps, whereas the gas pools in Permian limestones are naturally fractured traps, with fractures developod in each arch on these two blocks. Tracing a series of cross sections in a structure, the evolution of such a structure as the result of horizontal stress may be studied. In this paper, an actual example is presented. Such a study is halpful to explain the mechanism of the formation of various structural characteristics in the discussed area. Another distinction of the P-C structure from its corresponding surface one is the intersection of the strike of various blocks in the same structure. It shows that the fold had subjected to multiple actions of tectonic stresses in various directions and various orogenic stages. It seems here that some superposition of folds should be considered. Field practice shows that such intersection is usually associated with developed fracture system and will result in high capacity wells as well as large hydrocabon reverse.