The influence of surface-modified silica (SiO2) nanoparticles on the stability and pore plugging properties of foams in porous media was investigated in this study.The pore plugging ability of foams was estimated from the pressure drop induced during foam propagation in porous media.The results clearly showed that the modified SiO2 nanoparticlestabilized foam exhibited high stability,and the differential pressure increased in porous media by as much as three times.The addition of SiO2 nanoparticles to the foaming dispersions further mitigated the adverse effect of oil toward the foam pore plugging ability.Consequently,the oil recovery increased in the presence of nanoparticles by approximately 15％ during the enhanced oil recovery experiment.The study suggested that the addition of surface-modified silica nanoparticles to the surfactant solution could considerably improve the conventional foam stability and pore plugging performance in porous media.