Abstract: The decrease in sea level and the increase in seafloor temperature may lead to an upward shift of the base of the hydrate stability zone. This shift could trigger the decomposition of marine gas hydrates, resulting in the generation of overpressure within the sediment pore spaces near the base of hydrate stability zone. We developed a numerical model to simulate the dynamic movement of the base of the gas hydrate stability zone over the period of 0-25 ka BP in the Dongsha area, located in the northern part of the South China Sea. The simulation results indicate that fluctuation in seafloor temperature is the primary factor on the movement of the base of the hydrate stability zone, especially in the context of rising sea levels. The temperature fluctuation dominates the cyclic processes of hydrate formation and decomposition. An increase in bottom water temperature would result in an upward shift of the lower boundary of the stability zone, leading to the decomposition of hydrates and the subsequent release of significant amounts of methane gas. Notably, this response exhibits a lag of approximately 1-3 ka. Furthermore, the corresponding sediment layers that were drilled show an enrichment of molybdenum (Mo) elements, suggesting that the overpressure generated by the bottom boundary rise of the stability zone and the decomposition of hydrates may contribute to the formation of cold seep activities at seafloor. Therefore, the decomposition of gas hydrates may serve as a driving mechanism for cold seepage activities.