Abstract: Oula sheep is one branch of Tibetan sheep, which is different from other domestic and foreign breeds of sheep（Ovis aries）. Both male and female sheep are born with large horns, which is the result of natural selection under long-term grazing conditions, but its large horns are not conducive to modern efficient animal husbandry production needs. Many previous studies have mapped the main control gene of sheep hornless trait to RXFP2 gene on sheep chromosome 10, but the regulatory effect of RXFP2 gene in different sheep breeds is still different. In order to speed up the breeding of polled sheep breeds in the Qinghai-Tibet Plateau, 15 adult horned ewe and 15 adult hornless ewe Oula sheep（Ovis aries） were detected by genome resequencing, respectively, and F_ST was used to selectively eliminate the main selection genes for the angular phenotype. The CDS region and the upper and lower 50 kbp regions of RXFP2 gene of Oula sheep were scanned by 2 000 bp window and 1 000 bp step. Tajima′s D, π, and F_ST selection analysis were performed on the single nucleotide polymorphism（SNP） obtained. The results showed that there were strong selective signals in the RXFP2 gene and its downstream regions in Oula sheep. Four high quality SNP in the RXFP2 gene of Oula sheep were identified by SNP screening, which were synonymous mutations（g.29458690A＞G, g.29446067T＞C） in exon 9 and exon 14 of RXFP2 gene, and two non-synonymous mutations（g.29439053C＞T, g.29439011C＞T） in exons 17 of RXFP2 gene. All the mutant regions were in the strong selection region of RXFP2 gene of hornless and horned Oula sheep. The results of this study can provide technical and theoretical basis for molecular assisted selection related to the breeding of hornless Oula sheep breeds（strains）, and help speed up the early breeding of hornless Oula sheep breeds.