By recovery of erosion thickness of the latest Cretaceous and the latest Paleogene and the analysis of the maximum depth of Indosinian unconformity Tg0, it is suggested that the Paleozoic-Mesozoic hydrocarbon source rock have occurred late hydrocarbon generation and accumulation. Many ancient nose uplift axises in Indosinian unconformity Tg0 since the latest Cretaceous hydrocarbon generation indicate the hydrocarbon migration paths, directions and accumulation areas, and their changes from Himalayan to the present indicate favorable prospecting areas.