Based on the new high resolution 2D seismic data and drilling data obtained from the western Taiwan Strait and combined with the regional geological data and previous research result, the authors established the high resolution equitime stratigraphic framework of the western Taiwan strait and, on such a basis, determined the geological age attributes and sedimentary facies system characteristics. The results show that there are 6 third-order sequence boundaries in the Quaternary strata,which are correspondingly divided into 5 third-order sequences. The seismic facies in the study area are mainly sheet-like parallel-subparallel seismic facies, progradationa seismic facies, incised valley filling seismic facies, low-continuous filling seismic facies and filling chaotic seismic facies, with different seismic facies and their combinations representing specific sedimentary systems. According to the above analysis, it can be seen that the Cenozoic sediments are mainly developed in the sea-land transition zone, and alluvial/pluvial plain facies and coastal plain facies are mainly developed in the study area. The sedimentary evolution characteristics were hence analyzed to provide geological basis for fine exploration in the western Taiwan Strait, which has great guiding significance for future hydrocarbon exploration.