Complicated variability of the spatial distribution of soil textural layers is a typical characterist ic of alluvial soil.Quantificational description of soil profile structure is crucial to the study of land use and transport of soil water and solute.Based on observation of 139 soil profiles in a 15 km² region in alluvial plain,North China,a transition probability geostat istical model was used to analyze variability of the spatial distribution of soil textural layers.Results indicate that the distribution of soil textu ral layers is not merely stochastic,but shows a certain tendency of juxtapositional transference.When this model was used in the conditional simulation of indicator kriging method,the final three dimensional geostatistical realization of soil textural layers spa tial distribution reflected the cross correlation between different soil textural layers.The findings may serve as powerful support for further simulation of water movement and solute transport in the regional soil.