Many studies on land use conversion have been carried out to provide fundamental information for the general plan of the future. Land use transition probabilities were usually estimated by calculating the areas of land in which land use categories were changed. However, it should be noted that the spatial unit of land use transition is a lot. This study describes a land use conversion model based on transition probability of lots. Change of land categories, division of lots, demolishing of buildings and reconstruction of buildings are described in this model. As an application of the model, we discuss the effect of land use policy by simulating the land use transition in the future.