Abstract: In order to reveal adaptive characteristics of intestinal mucosal barrier structures in Tibetan goats and Tibetan sheep. The numbers of intraepithelial lymphocytes (IELs), goblet cells (GCs) and mast cells (MCs) in different parts of small intestine of 4 adult Tibetan goats and 4 adult Tibetan sheep were measured by histological method and the Scion image software analysis techniques method. Results showed that the number of GCs and MCs in different parts of the small intestine of Tibetan goats were significantly（P<0.05）higher compared to those in Tibetan sheep The number of GCs in duodenum, jejunum and ileum in Tibetan goats was higher than that of Tibetan sheep by 37.87%（P<0.05）, 21.43%（P>0.05）and 31.68%（P<0.05）, respectively. While the number of MCs in duodenum, jejunum and ileum in Tibetan goats was higher than that of Tibetan sheep by 85.20%（P<0.05）, 50.73%（P<0.05）and 22.52%（P>0.05）, respectively However, the number of IELs in different parts of the small intestine in Tibetan goats （36.35±0.98）was obviously lower（P<0.05）than that of Tibetan goats（48.84±2.12）. The results suggested that the intestinal mucosal barrier function of Tibetan goats was stronger than that of Tibetan sheep. The IELs played a crucial defensive barrier role in Tibetan sheep, while the GCs and MCs play an important mucosal immune defenses in Tibetan goats.