On the basis of the field geologic examination data, the paper systematically studies the conditions of the generation and migration and trap of oil and gas in Cuoqin basin. 
    There are seven sets hydrocarbon source rock in Cuoqin basin. The rock types of the source rock is mostly limestone. These source rocks are in Jiega formation,Langshan formation, Duoba members of Duoni formation, Xiala formation, Dewukaxia formation, Keerduo formation. The source rock of mud rock is mostly shale. It is in Chuanba members of Duoni formation. The result of organic geochemistry analysis has revealed that the source rocks in the Langshan formation, Xiala formation, Dewukaxia formation is better than others in Cuoqin basin.
    The reservoirs are mostly limestone and sandstone in Cuoqin basin. These limestone reservoirs are mostly in Langshan formation, Duoba members of Duoni formation, Xiala formation, Zhalongema formation, Dewukaxia formation, Keerduo formation. The sandstone reservoirs are mostly in Niubao formation, Chuanba members of Duoni formation, Zelong group, Daxiong group, Jienu group, Angjie formation. The reservoirs in Cuoqin basin are mostly inferior reservoir.
    The seals in Cuoqin basin are high quality seal. The best combinations of source rock and reservoir and seal in Cuoqin basin are that the source rock and reservoir and seal are same layer and that the source rock and reservoir is alternate layer.
    Petroleum migration has been confirmed by the surface indication and the microcosmic enclosure in Cuoqin basin.
    In Cuoqin basin, the main types of trap and petroleum pool are anticline trap and fault clock trap. The formation model of petroleum pool is different from each other in every synthem. In K₂-R synthem, anticline is the main type of petroleum pool. In J-K₁ synthem, the main type of petroleum pool is the anticline that has been modified by fault.
    Due to many times of tectonization that Cuoqin basin has been experienced, it is very disadvantage to the save of petroleum pool. The main aim stratum must be the later synthem.