Multi-episodic tectonic movement accompanied by multi-episodic hydrocarbon generation and hydrocarbon recharging and destroying makes the sealing capacity the key factor that control whether or not it is possible to find profitable oil and/or gas pool in the thick marine carbonate sequences developed in the South China.Outcrop sequence stratigraphic study around the ancient Majiang oil field indicate that there exist three kinds of sequences developed under the growth faults,the slope of the continental shelf and the mild ramp respectively.The hydrocarbon show is found mainly in the low-stand system tracts(LST) and the high-stand system tracts(HST) of the underlying sequence directly under the cover of the transgression system tracts(TST) developed in the upper sequence.The transgressive system tract in a sequence is the main cap rock of the ancient oil reservoir suggests that hydrocarbon exploration in the South china should emphasize the sealing effect of TST developed under the regional and the global sea-flooding,while the TST developed under the local sea-flooding may not enable the oil/gas pool survive multi-episodic tectonic movement.The difference of the hydrocarbon abundance in different types of sequences developed in the Majiang ancient oil reservoir enlighten that the sequence model developed in the marine carbonate should be systematically studied and then evaluate the sealing difference of the three system tracts.