Abstract:In order to find stronger linked microsatellite markers, 9 polymorphic EST-SSR loci were selected in German Merino grading crossing offspring F2 with Chinese Merino sheep, then the genetic polymorphism of group and the correlation between microsatellite markers and wool traits were analyzed. The results showed that the loci had rich polymorphism and 39 alleles was detected among 9 loci in the group and 6 of them had significance differences between genotypes. There were 5 loci related with natural length, 4 loci related with stretched length and 3 loci related with the diameter. The results of F test for the relativity of EST-SSR markers with wool traits showed that 33176918 and 33176988 loci had significant genetic effects in the natural wool length and average diameter, respectively (P<0.05). The study suggests that 33176918 locus has significant marker effect on natural length and CD genotype is the favorable genotype; 33176988 locus has significant marker effect on fibre diameter and BC genotype is the favorable genotype. These two loci probable have high linkage with genetic locus of wool traits.