Abstract:The vegetation map on the scale of one to two hundred thousandth in Beijing was digitized and analyzed with GIS software ARC/INFO. In this map, there are 72 lower level patch types in total, and they belong to 6 higher level patch types, viz. forest, shrubland, grassland, orchard, cropland and waters, which include 20, 28, 4, 7, 11 and 2 lower level patch types respectively. Several basic descriptive statistics and five types of probability distributions, which include Gamma, negative exponential, lognormal, Weibull, and normal distributions, were chosen to characterize the patch size distributions for all the patch types in Beijing area. The results show that the patch size distributions for most of the 72 lower level types and all the 6 higher level types are right-skewed. Therefore, normal distribution cannot be used to characterize the patch size distributions in this area; and each of the other four probability distributions can only depict part of the types. The patch types that can be characterized with lognormal distribution are relatively more, and those with negative exponential distribution are fewer.