In recent years,the success of unconventional shale oil and gas exploration and development has pointed out a new direction for obtaining oil and gas resources,and reminded petroleum geologists to re-examine the traditional oil and gas geological theory.It is necessary to combine the research progress in shale oil and gas with the traditional petroleum geological theory to form a new petroleum system theory.Based on research progress in hydrocarbon generation and reservoir from conventional to unconventional oil and gas,this paper preliminarily discusses the unified petroleum system and cooperative exploration strategy covering both conventional and unconventional system.The study of hydrocarbon generation extends from the hydrocarbon generation amounts at the generating peak to the description of the whole process of hydrocarbon generation,discharge and retention. Reservoir study extends from meter—millimeter inorganic pores with diagenesis to micron- nanoscale organic pores with diagenesis—hydrocarbon synergy.On this basis,the classification is proposed covering shale gas in narrow sense,shale gas in broad sense and conventional gas reservoir.Under the guidance of the new petroleum system theory,it is necessary to change exploration strategy based on the integrated evaluation of conventional—unconventional petroleum.Guided by the genetic relationship between conventional and unconventional oil and gas,this paper analyzes the formation,discharge and retention process of the same set of source rocks,and analyzes the ratio and spatial distribution between unconventional and conventional oil and gas,which helps to improve the efficiency and success rate of petroleum exploration.