Abstract: The Wan'an Basin as one of major Cenozoic petroleum basins in the South China Sea is a representative Cenozoic strike-slip pull-apart basin. Inferred from the calculations of balanced profile modeling, tectonic subsidence rates and sedimentary rates for the basinwide seismic reflection profiles, the Wan'an Basin may have experienced three phases of rapid tectonic subsidence. The sedimentary rates also came up to a climax from the 2.6 Ma onwards. A close correlation exists between the tectonic subsidence rates and sedimentary rates of the basin, which have exercised a major control on the generation, accumulation, migration and preservation of the hydrocarbons in the basin.