This paper researches the effect of the interfacial transition zone (ITZ) on the migration behavior of cations under the Accelerated Lithium Migration Technique (ALMT). Cylindrical mortars with different aggregate volume fractions (Vf) and w/c=0.5 were used. The result shows that when Vf ≤ 20 %, the Li+ steady state migration coefficient (Ds) is influenced by the dilution and tortuosity effects of the aggregate. The combined effect of ITZ and percolation occurs at Vf = 30 %, and the effects increase with the increase in Vf. Based on the experimental and regression analysis results, when the assumed thickness of ITZ = 20 μm, the approximate Ds of ITZ and percolated ITZ are 46.4 and 52.6 times the matrix migration coefficient.