Abstract: Digesta pH and activities of amylase,trypsin,chymytropsin,lipase and lactase in different part of small intestine(duodenum,jejunum and ileum)in lamb of Small Tail Han Sheep were measured. The results indicated that there were different digesta pH in different part of small intestine. Digesta pH in ileum were significantly higher than those in jejunum. Digesta pH in jejunum and ileum were significantly higher than those in duodenum. There were no significant change in digesta pH in different part of small intestine after the age of one month in lamb. There were different activities of amylase,trypsin,chymytropsin and lipase in different part of small intestine. Activities of amylase,trypsin,chymytropsin and lipase in jejunum were higher than those in duodenum and ileum, increased with the growth of lamb and there were no significant change after 3 months. There were different lactase activities in different part of small intestine. Lactase activities in jejunum were significantly higher than those in duodenum and ileum, decreased with the growth of lamb.