Abstract: Through comparison analysis of several main producing wells production of Chang-8 reservoir in Zhenting area,parameters of the hydrocarbon source rocks,reservoir properties,pore throat size,and distribution relationship of fracture crack,the research on main controlling factors of Chang-8 reservoir high yield has been carried out.The research results show the filling conditions of the main source rock Chang-7 are good,which lays the material basis for hydrocarbon enrichment.A good reservoir property,especially the good pore structure is one of the main controlling factors of Chang-8 reservoir high yield.Class-I and class-II faults with big displacement(> 30 m)were developed in this area,which led to hydrocarbon loss within a certain distance along the fracture,and it may damage reservoir to a certain extent.While the faults with small displacement,especially the fracture zone can not only provide good channel for oil and gas migration,but also improve the permeability of tight sandstone,thereby promoting reservoir relative enrichment and high yield.