Abstract: To identify S-genotypes of a few types of wild species originating from Gansu Province, S-RNase specific PCR were used. After cloning and sequencing of PCR products, the S-genotypes of 18 species native to Gansu were determined. The results were as follows:‘Linxiaxiangba’S₁₂S₂₁,‘Ganguheili’S₁₆ S₅₄,‘Kanglebaiguo’S_bS_i,‘Wudutianli’S₂₆S_i,‘Linxiahuangma’S₃S_e,‘Kanglesumuli’S₁S_h,‘Linxiasala’S₁₆S_e,‘Jiuquanchangbali’S₆S₂₂,‘Linyaomatianli’S₂₂S_d,‘Jiuquanmaili’S₆S₁₇,‘Manluwowoguo’S₁₂S₂₁,‘Wushantangli’S₈S₁₉,‘Kangleganchangba’S₂₂S_d,‘Hezhengganchangba’S₂₂S_d.‘Ganguxiangshui’and‘Lixianxinbapan’had a S_e-RNase gene. There was a S₂₆ in‘Linxiadadiaodan’and S₁₆ in‘Ganguhongxia’. Subsequent sequence analysis showed that there was a novel S-RNase in‘Ganguheili’, which was named S₅₄. The results would be useful for research of evolution of genes between different pear species, selection of pollinizers and design of crossing in cultivar improvement of pear.