This research focuses on the seismic characteristics of various fluid flow systems at the southern margin of the South China Sea. We have considered their associated seismic responses and hydrocarbon accumulations and determined the relationships between fluid flow and hydrocarbon migration. From amplitude anomalies and geometric morphology, we identify different focused fluid flow systems, such as mud diapirs/mud volcanoes, gas chimneys, pipes, and fault-related flow systems. We observe that gas-bearing fields associated with high-amplitude anomalous, low-amplitude chaotic, and “drop-down” reflection events serve as distinguishing features of focused fluid flow systems. These systems are affected by tectonic movements and sedimentation, and they are closely related to deep, high-temperature, and high-pressure plastic fluids. Furthermore, our investigations show that focused fluid flow systems, which preferentially develop in the weak parts of the strata, as well as associated faults and fractures, often act as conduits for hydrocarbon migration and accumulation. Therefore, these systems should be given the utmost attention during seismic exploration for hydrocarbons.