Abstract: Microsatellites are tandem repeats of short nucleotide motifs (1-5 bp long) dispersing widely and relatively evenly in eukaryotic genomes.The high degree of allelic diversity at each microsatellite locus provides ideal Mendelian markers for population and pedigree analysis.Understanding of microsatellite mutational m echanism will be helpful to appropriately use microsatellite markers for biological studies.Here we introduce the latest progress in microsatellite research,including its mutation,mutational mechanism,application (especially in relationship identification),as well as its pitfalls.