Based on observed data of textural layers from a lot of soil profiles in a 15km² area in a fluviogenic plain (North China Plain),this paper deals with spatial variations of some indexes of clay layers and probability distribution characteristics of different types of textural layers in the area by geostatistical method and general probability statistics.The results show that the maximum relative distances of the thickness and emerging depth of first clay layers,and the total thickness of clay layers in lm depth and 2m depth are all in the range of 1500-2000m,and that the thickness of each type of textural layers is distributed lognormally.