Abstract: According to traditional hydrocarbon genesis theory,it is accepted that organic maturity is affected by temperature,time and pressure.After summarizing exploration practices,it reveals that thermal maturity of organic matter is mainly controlled by temperature.So long as the temperature is high enough,substantial hydrocarbon can be generated from source rock.Tectonic movements do not only produce great amount of heat,but also make hydrocarbon generation and expulsion abruptly.Compressive process promote the hydrocarbon generation and migration.In addition,tectonic movements can form a set of traps,which shorten the time from generation to accumulation.Therefore,in areas where tectonic compression are well developed,though shallow buried source rock,they also have the capacity for hydrocarbon expulsion,and can form economic oil reservoirs.Based on these findings,the traditional theory that shallow source rock can not expulse oil should be broke,and regions of marginal basin with intense structural deformation should be taken into the exploratory frontier.