Abstract: Microsatellites are simple,tandemly repeated di to penta nucleotide sequence motifs flanked by inique sequence.They are valuable as genetic markers because they are co dominant,detect high levels of allelic diversity and are easily and economically assayed by PCR.Experiments reveal that microsatellites are distributed throughout the forestry genome.The most abundant microsatellite motifs reported in forestry are (AG) n and (AC) n。The occurrence of unclear microsatellites has been reported in several forest tree species such as pine,poplar,eucalyptus,and apple.SSR can be expected to complement existing RFLP,RAPD,AFLP maps, and are useful for genotype identification.gene and QTL analysis,marker assisted selection in breeding and pedigree analysis.