///On the basis of the summary of the seismic, logging and core features, the offshore subaqueous fan can be divided into four kinds of sub-facies (supply channel, inner fan, middle-fan, and outer fan respectively )and several micro facies, and there are significantly different characteristics between different facies belts. The steep-slope offshore subaqueous fan spread along the central fault in the form of string beadings and developed in low stand system tract, transgressive system tract and regressive system. The formation and evolution of the steep-slope offshore subaqueous fan were commonly controlled by three factors, namely, sediment supply, ancient landform and tectonic movement. The reservoirs of the steep offshore subaqueous fan usually are featured with more oil layers, thin single oil layers and different oiliness levels in different layers.