Abstract: In this paper,the geologic background of source rock development and the properties and distributive rules of source rocks in the Jiuxi Basin are dissected,the disposition relation of petroleum generating period to trap-developing period,the direction and pathway of petroleum migration,the characteristics and distribution of reservoir rocks,regional cover rock distribution and pool-forming rules are analyzed,and the basic regularity for the generation,storage,capping,migration,trapping and preservation of petroleum in the basin are summarized.On this base,the main petroleum pool-forming condtions which restrict the Jiuxi Basin are studied,and the favorable exploration domains and targets are pointed out.