Abstract: Ripley’s K function was used to analyse spatial patterns and association of S. transiliense populations in severe and extreme degradation regions. In a 20 m series spatial scale, the S. transiliense population was usually characterized by nonrandom (clumped) distribution in a seriously degraded region. The clumped intensity was different and showed a “clumped wave” phenomenon on a different scale. The S. transiliense population was usually characterized a by clumped distribution on a small-scale in an excessively degraded region, but when it reached the threshold of the clumped distribution, then it shifted to a random distribution. Analysis of the spatial association of two sizes of S. transiliense showed that the size 2 individuals had a clumped distribution in seriously degradation regions, but the clumped intensity of the larger individuals was weaker. The size 1 had a small-scale clumped distribution in the badly degradation region, with a shift to random or regular distribution with increase of the spatial scale. Size 2 had a random distribution. According to spatial association analysis, the two sizes of S. transiliense populations had a positive small-scale association in two degradation gradients, but the association waned with an increase of scale, and the scope of the scale was different when the two sizes of populations represent a positive association.