Abstract:In the study, 47 SSR polymorphic sites which have steady and specificity amplification were selected. PCR using 159 Eucalyptus germplasms accessions including 42 species of eucalyptus were applied to the genetic diversity analysis and clustering analysis, through the method of constructing a two dimensional database composed of the numbers of bands. (1) A total of 137 alleles obtained from the analysis of PCR results among all 159 accessions by 47 pairs of SSR primers with an average of 2.915 alleles per pairs of primers ranging from 2 to 7. (2)The results of genetic diversity showed that the average Shannons information index (I) was 0.181. The average observed heterozygosity(Ho) was 0.068, and the average value of polymorphism information content (PIC) was 0.182. The highest genetic diversity level was found in the three loci eSSRGR018, eSSRGR083 and eSSRGR109 by comprehensive comparison. These three SSR loci would play an important role in genetic diversity and germplasm identification among Eucalyptus germplasm resources. (3)The results of UPGMA analysis and principal coordinate analysis (PCoA method) were consistently indicated that 159 accessions were divided into two groups, and this classification agreed with the taxonomy of Hill & Johnson (1995) that based on morphology. Two cluster results showed that the relationship between Eucalyptus cloeziana and E. pauciflora was relatively higher genetic similarity and they were more likely to produce hybrids. The results in present research revealed high level of genetic diversity among the 159 Eucalyptus germplasms accessions including 42 species of Eucalyptus introduction in China. The 110 pairs of SSR primers could be applied to analyze Eucalyptus germplasm identification, effectively.