Many major blast resistance genes showed a high resistant level in rice-growing regions of Liaoning Province.However, the distribution of these genes in present rice leading cultivars of Liaoning Province has not been well investigated, resulting in the blindness of their utilization in rice breeding.In this paper, Piz-t (Pi2/Pi9), Pi-ta, Pik were amplified by the primers designed with the CDS sequence of three genes on 24 rice cultivars.Sequence comparison analysis revealed that the majority of nucleotide polymorphisms and the correspondent amino acid variation were associated with 3 genes of 24 rice cultivars.Here, we developed DNA markers derived from the CDS sequence and used these markers to screen 24 cultivars of rice germplasm.Through RT-PCR research, we identified 24 cultivars with the 3 resistance genes.Firstly, seventeen genotypes of Piz-t were detected in all 24 tested cultivars.The Piz-t sequences in all of the tested cultivars were different with those reported in NCBI website.On the whole,Piz-t is evolutionarily unstable.Secondly, eighteen genotypes of Pi-ta were detected in all 24 tested cultivars and four of them was same to reported resistance loci at 918th of amino acids.The pathogenicity assay also showed that the pathogenic ability was stronger than others.Thirdly, only two cultivars had been detected of the alleles of Piks.Based on sequence analysis and expression experiment of Piz-t/Pi-ta/Pik in the 24 cultivars, the distribution of three resistance genes in 24 rice leading cultivars have been detected.We also identified the alleles of 3 genes which has the function of resistance through interaction experiment of the plant and pathogen, and further explored the genetic evolution relationship between R genes and Avr-genes.According to this study and previously reported data, the rice varieties which carry Pik, Pi-ta and Piz-t alleles will play an essential role in antagonism to the epidemic fungus of rice blast in the Liaoning province.