Abstract: Genetic relationship and genetic diversity of 21 Pinus radiate samples originated from different geographic regions were revealed by SSR markers. The results showed that from 21 pairs of SSR primers, 13 pairs displayed obvious polymorphism and each primer could amplify 5-8 alleles� bands, genetic diversity index was 0.8076. Cluster analysis of the 21 samples was carried out and a dendrogram of genetic relatedness was developed on the basis of the SSR data. Moreover, 21 P. radiate samples could be clustered into 3 groups based on genetic similarity coefficient (GS= 0.804). Group 1 was composed of 17 samples of P. radiate, which were introduced from USA, Australia, Mexico and New Zealand. Group 2 contained 3 P. radiate samples from New Zealand and Group 3 included 1 P. radiate sample from New Zealand. Three out of 21 P. radiate introduced may be homegenetic. Because of high genetic diversity, extensive genetic variance and strong adaptability, the introduced New Zealand P. radiate can be widely used for population propagation, forestation in the dry-hot regions and restore the degenerating ecosystem in the upper Mingjiang river Basin.