Abstract: 【Objective】 To study cloning and sequence analysis of self-incompatibility S-RNase gene from 9 European plum cultivars 【Methods】 Leaf genomic DNA of 9 European Prunus varieties were amplified by specific PCR using two pairs of universal primers of Rosaceae, and the fragments were recovered.The cloned sequencing results were compared in GenBank database for homology and sequence analysis. 【Result】 Two bands were amplified from 9 European plum cultivars and the S genotypes of 8 European plum cultivars in 9 tested samples were identified.The S genotypes of Richard Early and Stanley were S1S9, and French and Silvia were S1S5.The S genotypes of Uzigan 1, President, Decbrowice and Nmpress were S1S11, S6SSJ, S1SSJ and SSAS11, respectively.Only one S1-RNase allele was identified in Tacheng Suanmei, but the S genotype was not identified.Gene frequency analysis showed that the frequency of S1-RNase gene was the highest, and the frequency of S6-RNase and SSA-RNase gene was the lowest.The phylogenetic tree of Rosaceae showed that SSA, S6, S9, SSJ and S5 were closely related to each other.The S-RNase genes of the tested Prunus species could not cluster into a single subclass, but were interleaved with each other in each branch of Prunus. 【Conclusion】 The S genotype of European plum is composed of two different S alleles.Of the nine samples identified, eight European plum cultivars yield the complete S genotype, in which S1-RNase gene appears the highest frequency.The S gene differentiation of Lyaceae plants is earlier than the formation of each species.Evolution within the S gene species takes place in separate systems.