This study looks at the use of X-ray computed tomography (XRCT) technique to determine the internal structure of carbonated lime treated kaolin. The results show that the formation of calcium carbonate (CaCO_3) along the depth of carbonated kaolin can be determined using XRCT. The carbonate formed shows to be evenly distributed deep down the lime treated kaolin. The air voids of carbonated lime treated kaolin decreased compared to the corresponding non-carbonated lime treated kaolin. CaCO_3 content obtained from XRCT compared favourably with that from TGA and calcimeter technique. XRCT has the potential for the determination of internal structure of carbonated lime treated soil.