Abstract: In order to investigate the developmental characteristics of confined sheep rumen in morphology, the sheep aged 40, 60,120, 180 and 240 days were randomly selected respectively, and their rumen volume, relative rumen volume, and the height,width and density of papillae in mucosal layer of rumen were determined. The results revealed that the rumen volume and relative rumen volume of sheep was increased along with the increase of age in days; After 60-day-old, the rumen volume was increased along with the increase of age in days（P〈0.05）; Before 120-day-old, the relative rumen volume was significantly increased（P〈0.05）.The height and width of papillae in mucosal layer of rumen was increased along with the increase of age in days; Before 60-day-old, the density of papillae in mucosal layer of rumen was increased along with the increase of age in days; After 60-day-old,the density of papillae in mucosal layer of rumen was reduced along with the increase of age in days. The morphological changes of papillae in varied parts of rumen are different in significant differences.