Abstract: The Lishui-Jiaojiang Sag is a typical fault basin in China with great oil potential. Multiple factors, such as core facies, logging facies, seismic attributes, seismic facies, biofacies, organic geochemistry, rock color, paleogeomorphology and structures, are studied in details in this paper for the Paleogene Mingyuefeng Formation in the Lishui-Jiaojiang Sag. The spatial distribution pattern of these factors is systematically analyzed to decipher the depositional systems of the sag. There are four types of depositional systems in the Paleogene Mingyuefeng Formation in the sag, i. e., fan delta system, delta system, sea system and gravity flow system. The fan delta system is developed in the east on steep hills under the control of syndepositional faults, the delta system developed in the west on gentle slope, and the gravity flow system deposited under the control of intrabasinal secondary faults. The comprehensive analysis of multiple factors is proven effective for the depositional system analysis.