Abstract: Porous media is firstly simplified as a bunch ofconstricted capillary tubes related to grain diameter, particle arrangement,pore-throat scaling ratio and saturation of immobile water. Based on thedeformation characteristics of a single bubble in throat and pore of porousmedia, pressure distribution of fluid phase is derived from the conservationof momentum in a single pore unit, to obtain the equation for pressuredistribution in porous media. Moreover, the experiments on flow foam inU-shape sandpack are investigated. The results demonstrate the lineardecreasing pressure distribution of steady foams in porous media and theinfluencing factors, i.e., pore-throat structure, flowing rate and qualityof foams, interfacial tension of gas and liquid, bubble size in pore media.Furthermore, the results show further that pore-throat structure and foamquality have the most influence on the blocking ability of foams in porousmedia.