From the point of geochemistry, and combined with such geological elements as fracture distribution, sedimentary and tectonic conditions, according to accumulation systems classification principles, the Baiyun deep-water sag is divided into two broad classes，seven small classes of accumulation systems, that is, four accumulation systems in Panyu lower uplift in the western part and three ac?cumulation systems in Liuhua–Liwan district in the eastern part. We summarize the respective characteristics of different accumulation systems based on the following classification properties: sedimentary environment, crude oil classification, material source, oil source, crude oil maturity, oil and gas migration and accumulation, migration dominant factors. Three typical kinds of accumulation pat? terns are put forward on the basis of accumulation systems division, namely, open, closed and complex accumulation pattern. The open accumulation pattern has the features of multiple and developed faults, the faults play an important role in oil and gas migration and accumulation. The closed accumulation pattern is characterized by oil evolving into high maturity stage and cracking into gas thermally,fractures, ridge-like structures and sands are oil and gas migration channels. The complex accumulations are controlled by faults, diapir zones and ridge-like structures, high-degree evolution of petroleum cracking into gas thermally. According to the accumulation systems division in Baiyun deep-water sag, and the comprehensive analyses of three kinds of accumulation patterns, it indicates that, the N2, N3, N4 and E2, E3 are favorable migration and accumulation areas with good exploration prospects.