Abstract: To study the localization and expression of the leptin receptor(OB-R) in various tissues of Small Tail Han Sheep. In the study, we analyzed the expression of leptin receptor in neuroendocrine and reproductive system of Small Tail Han Sheep with immunohistochemistry and Western Blot. The results demonstrate: positive brown granules were located in some of the cells of hypothalamus, pituitary, ovary and uterus. Three bands with a molecular mass close to 120,110 and 98 ku were identified by Western Blot There were different amount of expression in different organization. There were a plenty of expression in many tissues, which showed that OB-R plays a key role in the reproductive function of Small Tail Han Sheep.