Abstract:  Rice blast was one of the widespread fungal diseases constraining rice stable production. Utilization of host resistance （R） genes provided the most efficient and economical approach to tackle this disease. As of now， 27 rice blast R genes had been characterized. With respect to their distribution in rice genome， these 27 R genes located in 14 genetic loci， suggesting that each locus had about 2 allelic genes. Moreover， allelic R genes at the same locus shared extreme sequence similarity to each other. Compared to those functional alleles， nonfunctional ones in the susceptible varieties were typical pseudogenes due to various sequence mutations in some R genes loci. Some R genes loci in susceptible varieties had alleles with significant sequence difference and distinct genomic organization. The distribution pattern of multiple allelic R genes in the same locus in rice genome provided ideal reference information for homology\|based gene cloning including allele mining. In this review， we elaborated the current progress on the cloning of rice blast R genes， their structural classification and distribution on chromosomes. We also discussed the application and prospective of allele mining for cloning novel alleles in some R gene loci.

Key words: rice blast, resistance gene, gene cloning, multiple alleles, allele mining