The use of lime to improve the behavior of marine clays has been in practice in several parts of the world over a long period. In this paper, the beneficial changes occurred in a marine clay due to the diffusion of lime from lime column and lime injected points have been studied using XRD and SEM techniques. The new compounds formed have been identified using the XRD technique. The diffusion of lime has been established through the measurements of lime content and pH from the samples taken at different locations and at various time periods. The transformation of the soil particles due to lime attack on the clay minerals present in a marine clay has been studied and discussed. ©ASCE.