This report identified S-RNase genes (S genes) of sweet cherry (Prunus avium L.), presented the sequences of S genes by using a pair of specific primers PruC2 and PruC4R based on the conserved regions C2 and RC4 of Rosaceous S-RNase genes and researched the S gene specific products from the genomic DNAs of different cultivars in which most of the S genotypese were unknown. The bands of PCR were cloned and their sequences were compared in GenBank. Four S genes were defined and the conclusion was made that all the same bands from PCR in the agarose gel had the same length and sequence of nucleic acid and were the same kind of S gene. The lengths of the amplified S genes are as follows: S1 is 677 bp, S3 762 bp, S4 945 bp, S6 456 bp. The S genotypes (S gene genotypes) of the tested self-incompatible cultivars were identified as follows: 'Hongdeng', 'Hongyan' and 'Early ruby', as same as 'Van', were S1 S3; 'Jueze', 'Hongfeng' and 'Napoleon' were S3S4; 'Dazi' was S1 S6; 'Changbahong' was S1 S4; 'Elton' was S3S6. The self-compatibile cultivars 'Waiyin No.7' and 'Stella' had the same S genotypes S3 S4'.