Quasi-foreland basins is a kind of complex reformed basins in Western and Central China which are actually superimposition of prototype basins formed in different stage.The basins were effected by different tectonic settings and controlled by stress fields during basin evolution

thus forming different sedimentary systems and sequences.Hence

tectonism and sedimentation were main factors controlling multiphase hydrocarbon generation and multiphase pool-forming of the basins.The development processes of the basins consiste of two stages of hydrocarbon generation and pool-forming conditons

and the sedimentary sequences themselves also possessed source-reservoir-cap rock complex conditions.To explor oil in this kind of basins

one should pay attention to hydrocarbon generation conditions

study the conditions of pool-forming and late preservation of the pools.