Abstract: This paper dealt with a numerical simulation of the flow resistance and heat transfer characteristics on fifteen different laminated porous wall models.The effects of pin-fin's fill ratio and diameter ratio were investigated.This investigation considered fifteen geometry models: pin-fin's fill ratio and diameter ratio were varied from 0.15 to 0.35 or from 0.3 to 0.7 respectively,while pin-fin's fill ratio was kept at 0.25.Length and height of the whole model were 4 mm and 2 mm respectively;height of pin-fin was 1 mm,diameter of holes in entrance surface and coolant supply plane was 0.5 mm,and the injection angle of outlet with the coolant supply plane was 60°.Results are presented as the coefficient of flow resistance and the heat transfer efficiency.The results show that:(1) the increase of pin-fin's fill ratio is propitious to decrease the flow resistance and improve the heat transfer efficiency,(2) the increase of main pin-fin's diameter is propitious to decrease the flow resistance,and the heat transfer efficiency is best when main pin-fin's diameter is same with assistant pin-fin's diameter.