Abstract: OBJECTIVE To study the effects of indomethacin on function of stomach in rats and its mechanism. METHODS Rats were randomly divided into control group, low-, middle- and high-dose of indomethacin groups. The gastric acid secretion, protease activity and serum gastrin levels were determined. RESULTS Compared with control group, indomethacin significantly increased gastric acid secretion, increased the rate of gastric acid secretion and increased pepsin activity, and promoted the secretion of gastrin. CONCLUSION Indomethacin could promote gastric acid secretion, increase pepsin activity, which facilitate their secret factors of gastric secretion.