Hydrocarbon carrier system is important as“the bridge and vinculum”between the oil sources and traps in hydrocarbon accumulation process. Based on previous study，the Neogene was taken as the target layer to analyze the measured formation pressure coefficient of four oil fields in the central uplift belt of Huanghekou sag，and then the effect of different formation pressure coefficient on oil and gas migration was discussed within the sequence stratigraphic framework.The results obtained show that there were three kinds of hydrocarbon coefficient in the central uplift belt of Huanghekou sag under the normal pressure condition. They were low pressure coefficient-high permeability carrier system，high pressure coefficient-middle permeability carrier system and middle pressure coefficient-high permeability carrier system. In the central uplift belt of Huanghekou sag，the low pressure coefficient-high permeability sandstone reservoir was the main carrier layer in Guantao and V oil group of lower Minghuazhen Formation in sag-gentle slope belt and inⅢoil group of lower Minghuazhen Formation in gentle slope-salient area. The high pressure coefficient-middle permeability sandstone reservoir was the main carrier layer inⅢoil group of lower Minghuazhen Formation in sag-gentle slope belt and the middle pressure coefficient-high permeability massive sandstone reservoir was the main carrier layer in salient area.