Grea t South Basin has experienced three tectonic evolution stages, i.e. the rifting, the depression and the passive margin stages. Three set of source rocks developed in the basin, which are Hoiho Group coal-measures that formed during the rifting stage, and Taratu coastal plain coal-measures and Wickliffe marine mudstone that formed during the depression stage. In the light of Zhang′s "source-heat co-control" theory, it is indicated that Hoiho Group coal-measures should be the principle gas source rock owing to their deep burial and large effective volume with abundant organic matter and high thermal evolution. Besides Taratu coal-measures may be also effective source rock in local areas. It is believed that Central Depression where thick source rocks develop is of giant hydrocarbon potential.