Abstract: Source rocks are the material basis for oil and gas generation. Based on newly acquired high-quality two-dimensional seismic data and comprehensive research results, we recognized four sets of seismic sequences and five stratigraphic units controlled by unconformity in seismic reflection interface in the Zhongjiannan Basin, and analyzed the sedimentary evolution characteristics of the basin. It is speculated that three sets of main source rocks were developed in the Zhongjiannan Basin, i.e. Middle Eocene lacustrine source rocks, Upper Eocene-Oligocene lacustrine source rocks and ocean-land facies source rocks, and Lower Miocene to Upper Miocene marine source rocks. Through analogical analysis of the surrounding basins, the seismic facies characteristics of the three sets of source rocks were determined. The thickness and distribution of mudstone in the three sets were estimated in the percentage of mud in different sedimentary facies zones. This study provided a reference for evaluating oil and gas resources, analyzing favorable secondary structural zones, and exploration planning.