The Late Palaeozoic aulacogen（D-P 1 ）basin and later syneclise depression（P 2 -T 2 ）basin in the Great NanpanjiangˉYoujiang area are located mainly in Guangxi Province and also stretch into parts of Yunan，Guizhou，and Guangdong provinces. They experienced deformation due to the collision and closure of the AilaoshanˉHonghe prototethys ocean during the IndosinianˉEarly Yanshanian period. The over thrusting of three basal detachment bodies（MaguanˉHejiang，Xuefengshan and Yukansan）helped to form progressive tectonic deformation domains with strong to weak thrustingˉfolding in different places. The LiupanshuiˉZiyunˉDuan strikeˉslip belt acted as the deformation transform zone in the depression. These tectonic deformation domains controlled the generation，accumulation and distribution of marine oil/gas in the area.