Genetic diversity of 60 Myanmar Sein Ta Lone mango accessions from 21 orchards within three locations in Kyaukse District was studied in this research. 9 Simple Sequence Repeat (SSR) markers were used to study the genetic diversity and phylogenetic relationships among the collected mango accessions. Total of 48 scorable bands were observed on amplification with the sizes ranging between 110bp and 369bp. Polymorphic information content (PIC) of 9 SSR markers were 0.265 to 0.74 with an average of 0.421 per marker. The optimal annealing temperature of the primers was 42 to 58°C in range. By using UPGMA cluster analysis, it grouped all the accessions from three locations with a genetic similar coefficient between 0.68-0.96. There was no clone in each orchard and the least dissimilarity was ~ 4% in SM orchard in location 1, SH orchard and SPu orchard in location 2 and STM orchard in location 3. In the present study, analysis of genetic study by means of microsatellite markers showed high genetic diversity of Sein Ta Lone mango accessions and a mix pattern of the accessions within three locations.