Abstract: The spatial structure of genetic diversity among 17 populations of Cryphonectria parasitica in China was investigated using RAPD markers with the spatial autocorrelation analysis. The result revealed a lack of spatial structure of genetic variation among populations of C. parasitica indicating a fact that genetic variations of the most polymorphic loci were randomly distributed. However, cline depression, lump, or double cline structures of the genetic variation were found at some RAPD loci with significant Moran's I in several distance classes. The spatial patterns of genetic differentiation in populations appeared to be a combining result of long-distance gene flow, human activities, local effects of geographic isolation and reproduction behaviour of C. parasitica, and it speculated that Southwest China could be a possible center of C. parasitica origin in China based on the cline pattern at some loci.