The thrust-and-fault belt of the southern Subandean of Bolivia is a mature exploratory area (~300 km2/exploratory well) even if the deep mega play (older than Los Monos Formation) is still an intermediate exploratory area (~800 km2/exploratory well). The analysis of the existing fields of the area shows that most of them are not filled up to their spill point. This is mainly due to charge limitation related to the geological history. In order to reduce uncertainties and risk during prospect assessment, a geological synthesis of Bolivia has been carried out. One of the outputs of this study is a better understanding of the sedimentary architecture and especially the source rock distribution, even if more works are needed to fully characterize them. The thermal calibrations associated with geological data indicate the existence of a thermal event that took place at the end of the Triassic. As a consequence, the geochemical models calculate two expulsion pulses. The most important one occurred at the end of the Triassic - Early Jurassic. The second pulse, related to the Andean tectonics, can be subdivided locally into two phases: a phase previous to deformation during foreland sedimentation and another phase associated with sedimentation and erosion during deformation.During the last "tectonic" phase, traps may be charged with hydrocarbons expelled from the synclines and from the anticlines. The expulsion mechanisms in the synclines are mechanical compaction and sometime increase of maturity if sedimentation occurred during deformation. In the anticlines, depressurization during uplift is the main mechanism which originates expulsion.A specific methodology has been developed in order to assess the charge of a given trap. Charge is computed as the product of the fetch area (FA), the remaining potential (SPI) of the source rock at the age (Age) of the trap formation, and the efficiency ratio (PSY). The last factor is calibrated with the existing fields. The SPI is evaluated through 1D geochemical modeling calibrated through a red of more than 200 wells.The occurrence of the main expulsion phase at the end of the Triassic (o beg Jurassic) could open the exploration of Southern Bolivia to new plays such as the Paleozoic pinch out on the basement or stratigraphic traps within the Carboniferous glacial deposits. Other conceptual plays could be considered looking for structural traps older than Jurassic