Tagging of restorer genes for wild abortive (WA) CMS source by studying a 222 individual plants from a F 2 population of a cross between IR58025A £ IR42686R. The restorer line IR42686R that was used in this study had been previously derived through random mating composite population (RMCP) involving 12 parents facilitated by IR36 genetic male sterility. Four Rf genes were tagged to simple sequence repeats (SSR) markers on chromosomes 1, 7, 10, 12 by recessive class analysis. The recombination frequency between a positive marker and Rf locus was calculated using maximum likelihood estimator assuming that all the 46 extremely sterile individual plants were homozygous at the targeted Rf locus. The recombination frequency between the marker and the restorer trait were converted to genetic distances using Kosambi function. A new Rf locus designated as Rf7 on chromosome 12 was found to be linked to RM7003 at a genetic distance of 13.3 cM (LOD 6.12). We report here Wrst, a new molecular marker (RM 6344) linked to Rf4 locus on chromosome 7 that was previously mapped by trisomic analysis. RM443 and RM315 were Xanking the Rf3 gene at a genetic distance of 4.4 (LOD 10.29) and 20.7 cM (LOD 3.98) on chromosome 1, respectively. The Rf6 was Xanked on both side with SSR markers RM258 and RM591 at a genetic distance of 4.4 (LOD 10.29) and 23.3 cM (LOD 3.39) located on chromosome 10. The random mating composite population is an excellent breeding approach to develop superior restorer lines and for pyramiding diVerent Rf genes of diVerent CMS systems. Rf genes tagged with closely linked SSR markers would be facilitating marker assisted selection (MAS) in hybrid rice breeding program by reducing time and workload for identifying potential restorers.