Abstract: A cold-state experimental setup was built to study the constructional and operating parameters affecting the gas/air flow direction and flowrate in pelletizing shaft furnace (PSF). Some conclusions are therefore drawn that constructional and operating parameters are both the main influencing factors on the gas/air flow splitting in PSF. Among the operating parameters, the flowrate ratio of roasting gas to cooling air, i.e. the inflow flowrate ratio k is the key influencing factor on gas/air flow splitting, and the flow-down roasting gas/air tends to increase and the flow-up cooling gas tends to decrease with the increase of inflow flowrate ratio k, and vice versa. It is found that k is linear relation to the flowrate ratio of the cooling air into internal vertical air channels (IVAC) to the flow-up roasting gas under certain operating conditions. Among the constructional parameters, the widths of both roasting zone and IVAC and the heights of both preheating-roasting zone and soaking zone are the main influencing factors on gas/air flow splitting in PSF. In case the width of roasting zone increases or the width of IVAC or the height of preheating-roasting zone decreases, the flow-up cooling air tends to decrease and the flow-down roasting gas tends to increase with the critical k increases.