Abstract: Based on the structure characteristic of self-incompatibility gene and the gene group sequences of 46 S genes in Oriental pear cultivars，86 probes for S-RNase detections were designed and oligonucleotide genechip was established. In order to detect the S-genotype of pear cultivars，the PCR products of S-RNase were amplified by Cy3-labeled primers and hybridized with the microarray. The cultivars with known S-genotype such as Huali 2 were hybridized with the genechip and 27 cultivars with unknown S-genotype were S-genotyped using the genechip. The DNA sequenced results of Huali 2，Xiuyu and Deshengxiang pears and randomly selected unknown S-genotype cultivars were consistent with the microarray analyses. In conclusion，the oligonucleotide genechip provided an accurate and reliable method for detecting S-genotype of pear cultivars.

Key words: pear, self-incompatibility, S-genotype, oligonucleotide, genechip