In order to investigate the effect of eluviations on the mechanic performance of lime stabilized expansive soil, laboratory tests were conducted to reveal the influencing rules of lime proportion and age on the swellshrink properties of stabilized expansive soil. An optimal lime proportion was derived, a measuring device of eluviations was designed and the detailed test steps were given for reference. Besides, the variation law of the content of Ca2+ and the strength indexes with leaching days were discussed according to leaching tests. Based on the results of the laboratory tests, it is found that the cohesion force of the stabilized soils decreases with the decrease of the content of Ca2+, however, the internal friction angle remains constant. The influence of the decrease of the content of Ca2+ on the strength is disadvantageous to the long-term performance of subgrade.