In the present study we evaluated the amount and distribution of genetic variation by using RAPD marker variation of 12 markers loci in three broodstock groups of rainbow trout. A total of 47 polymorphic bands were observed in Iranian strain, average number of bands was 10 and average number of polymorphic bands per primer was 3.92. The total detected bands in rainbow trout strain originated from French, was 120 bands with an average number of 10 bands per RAPD primer. A total of 117 amplified were detected in Norwegian population, with an average number of bands and average number of polymorphic bands per primer was 9.75 and 2.58, respectively. Data for observed and effective number of alleles, Nei’s genetic diversity and Shannon’s information index for all the three populations were 1.31, 1.20, 0.120 and 0.170, respectively. The mean coefficient of gene differentiation value and the estimate of gene flow across the populations were found as 0.299 and 0.171, respectively. The Nei measures of genetic distance and identity between pairs of rainbow trout strains indicate that the strain originated from France and Iran has the highest genetic identity, while the fish originated from Norway and France showed the greatest genetic distance
