The research on the residual saturation of a non-wetting phase fluid is one of the main focuses in the field of multiporous media and multiphase flow. The saturationcapillary pressure (S-p) relationships and the residual air saturations were investigated under consecutive dryingwetting cycles in an airwater two-phase sandy medium. Results showed that

when the initial water saturation in the first imbibition process was close to that in the second imbibition process

the residual air saturation of the first imbibition process was also close to that of the second imbibition process. The residual air saturation increased with the increase of the initial water saturation in all the imbibition processes. The magnitude of the residual air saturation in the current imbibition was obviously affected by its former imbibition process. Large differences were also found between the residual air saturations predicted with the Land model and those measured in the column tests. It indicated that the effect of the initial water saturation on the residual air saturation was more significant than that of the circular number of the dryingwetting cycles.