Abstract: The discussions are made on the influence of fluid-flowing convection over the formation and distribution of secondary pores.It is pointed out that the upwelling of fluid-flowing should cease in the depth of 4000m in the reservoirs of the depression due to the barrier fault of upward dipping players,the existence of overpressure and insufficient fluid source.Therefore,the thermal-cyclic convection flowing is predominated and the continuous transformation of soluted material took place by the convection flowing,bringing about the formation of secondary pores and diagenetic traps in deep part of the Dongpu Depression