This study investigated water distribution patterns and preferential flow characteristics in six porous media with different profile structures (i.e. homogeneous fine media, homogeneous coarse media, fine media overlying coarse media, coarse media overlying fine media, fine media containing horizontal coarse layer, and coarse media containing horizontal fine layer) using dye tracing technique. The results showd that when water infiltrated from coarse to fine media, the hydraulic barrier effect inhibited the formation and development of preferential flow. In contrast, when water infiltrated from fine to coarse media, the capillary barrier effect promoted the formation and development of preferential flow. Both hydraulic and capillary barrier effects reduced the infiltration depth of water in the layered media profiles, leading to a distinct discontinuous distribution of moisture along the infiltration direction in the layered porous media profile. The preferential flow heterogeneity was the highest in the homogeneous fine media profile, the lowest in the coarse media overlying fine media profile, and higher in the media profile containing horizontal layered profile than in the media profile containing two different layers.