Simple sequence repeats (SSRs) are molecular genetic markers which are assayed with PCR using specific primers. They have a broad range of applicability in genomic research of many and diverse animal and plant species. SSRs are widely distributed throughout the genome, but are mainly found in the centromeric and eurochromatin regions. The search for and development of SSRs require a lot of efforts. However, with the successful sequencing of whole plant and animal genomes and the development of new instruments and methods, the number of SSRs markers developed and deposited in GenBank has increased exponentially. Due to high degree of polymorphism, one of the main applications of the SSR is in genetic diversity studies. The achievements and progress in this area have helped considerably applied and basic research, and conservation and exploitation of plant germplasm. By a high density molecular mapping of the genome using SSR markers associated with the genes biological traits of agricultural importance are identified. On the basis of the mapping results, SSR can be used for breeding with the aid of marker assisted selection (MAS) and cloning of the target gene (map - based cloning).