Lime stabilization is one of the techniques used to improve the mechanical properties, particularly the strength of soft clay soil. However the effectiveness of lime at long term is still ambiguous. This paper aims to determine the suitability of lime for stabilizing tropical kaolin clay soils, and to assess typical changes in soil structure due to mineralogical influences at different during period and lime content in both short and long term. The microstructure characterizations have been investigated using x-ray diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). Furthermore, to illustrate the effect of lime on the strength, series of laboratory tests were carried out by unconfined compressive strength. The results indicated that the addition of lime resulted in an improvement in compaction properties. In addition, the unconfined compressive strength (UCS) of stabilized clay has increased with the addition of lime. The influence of the time factor on the development of strength lime treated samples was equally proportional with the lime content factor. The formation of calcium aluminate silicate hydrate (CASH) was observed from the XRD test after 200 days, and the presence of the cementious products were further verified in FESEM analysis. It is therefore, proved the effectiveness of lime to stabilize kaolin clay in long term duration.