In order to have in-depth understanding of the influences of heterogeneous porous structure inside saline aquifers during carbon dioxide injection，a two-phase flow mathematical model was proposed to describe the imbibition process of the supercritical carbon dioxide-brine system，in which a lognormal distribution of porosity was introduced to represent heterogeneity of porous saline aquifers.The model also featured the imbibition process at varying densities and viscosities of supercritical carbon dioxide that were correlated to local pressure and temperature of saline aquifers.Numerical simulations were conducted to investigate the influences of process parameters during injection and characteristics of saline aquifers on injecting behavior and saturation distributions of supercritical carbon dioxide in the saline aquifers.The results showed that injection pressure was dependent on the depths and volumetric average porosities of saline aquifers.It was less affected by the porosity distribution of the saline aquifer.However，the saturation distributions of supercritical carbon dioxide in saline aquifers were strongly affected by the porosity distribution.When the total volumes of saline aquifers were identical，the storage capacity of a deep saline aquifer was less than that of a shallow aquifer，whereas the injection pressure in the former case was larger than that in the latter case.For the purpose of maximizing the storage efficiency，an appropriate injection rate needed to be chosen during carbon dioxide injection.The proposed method would provide an insight into carbon dioxide sequestration in saline aquifers，and it would also be a tool for evaluating the consequence of injection.