Abstract:Abstract Estrogen receptorα (ERα) gene plays an important role in the process of animal breeding. It has been considered as the main gene affecting the litter size of swine, but it is hardly studied in goat (Ovis linnaeus). In order to reveal the effects of ERa gene on reproductive traits of Guizhou local goat, the polymorphism of ERα gene 8 exons was detected by direct sequencing and the ERα mRNA expression in Qianbei Ma goat hypothalamus, pituitary and gonadal axis was detected by qRT-PCR. The results showed that C127T existed in the eighth exon of ERα gene of Qianbei Ma goat and Guizhou black goat. The C127T was a missense mutation and caused the change of mRNA secondary structure and encoding protein of ERα gene. CC, CT and TT genotypes were detected at C127T locus of the eighth exon of ERα gene. The Qianbei Ma goat with CC achieved significant difference level compared to CT and CC genotype. But the Guizhou Black goat did not reach significant differences. qRT-PCR results showed that the ERα gene in 2 groups (single lamb group and more lamb group) were expressed in 5 tissues of the Qianbei Ma goat. The highest in ovaries, the lowest in the fallopian tube, and the mRNA expression in the two groups of North Guizhou sheep tissues did not reach significant levels (P>0.05). These results indicated that C127T mutation of ERα gene might have an effect on reproduction traits of local goats in Guizhou province. This study provided the theoretical basis for fostering the high fecundity lines of local goats in Guizhou.