Through dynamitic analysis of the source kitchen and accumulative process, a couple of factors, such as development of organic rich marino-clastic interval, type of tectonic-deposition, effect of source-consequence resulted from source kitchen evolution in high-over mature phases and the quantitative relationship of the intensities of hydrocarbon generation and non-tectonic escape, were taken to understand the main geological and geochemical controls on the efficient hydrocarbon supply for the gas accumulation of marine sequences in south China. The capability of efficient hydrocarbon supply is one effect that integrates nature of source rock, type of tectonic-deposition, habit of source kitchen, the intensities of hydrocarbon generation and dissipation of gas through the time. The condition of hydrocarbon supply in the superposed basins of south China can be ranked as follow as: ‘Excellent’ with the efficient supply exceeding 20×108m3/km2，’Good’ with the efficient supply up to (10～20)×108m3/km2, ‘Moderate’ with the efficient supply up to (1～10)×108m3/km2 and ‘Poor’ with the efficient supply less than 1×108m3/km2. According to the criteria, a preliminary revalue was made to evaluate the capabilities of efficient hydrocarbon supply of the marine sequences in south China.