Abstract: Objective To study the effect and mechanism of flavonoids from Pongamina pinnata roots(RPF)on gastic ulcer induced by pyloric-ligation in rats.Methods The anti-gastric ulcer effect of PRF was observed with gastic ulcer induced by pyloric-ligation.The effcets of PRF on gastric secretion and mucus secretion in rats were studied with pyloric-ligation.The expression of epidermal growth factor(EGF)was detected by mimunohisto chemistry.The contents of gastrin in pyloric-ligation rats were determined by radio mimunoa ssay.Results The index of gastric ulcer of model was 4.37?0.69.The medium and high do sage of PRF inhibited markedly gastric ulcer induced by pyloric-ligation wtih inhibition ratios of 40.04% and 51.49%,respectively(P<0.01).The mild and high do sage of PRF also obviously inhibited secretion of gastric acid and promoted the secretion of gastric mucus(P<0.01).Compared with the control guoup,the medium and high do sage PRF group showed decreased serum gastrin(P<0.05,P<0.01).Conclusion PRF may inhibit gastric ulcer indued by pyloric-ligation.The mechanism of the effectmight be associated with the decreased secretion of gastrin and increased expression of EGF,which inhibits the secretion of gastric acid and promots the secretion of gastric mucus.