A cDNA of 417 bp encoding an S-RNase gene, named PA S3, was isolated from apricot, Prunus aremeniaca. Nine S-alleles, S-1-S-9, were recognized by S-allele-specific PCR and confirmed by Southern blot analysis using PA S3 as probe. The S-genotypes of the six cultivars were determined and the results of self- and cross-pollination tests among the six cultivars were consistent with the predicted S-haplotypes by PCR analysis.