This Study evaluated the inhibitory action of $luteolin-7-O-{eta}-D-glucuronopyranoside$, luteolin which was isolated from Salix gilgiana leaves, and omeprazole on reflux esophagitis and gastritis in rats. Reflux esophagitis and gastritis were induced surgically and by the administration of indomethacin, respectively. The intraduodenal administration of $luteolin-7-O-{eta}-D-glucuronopyranoside$ decreased the ulcer index, injury area, gastric volume and acid output, and increased the gastric pH compared with luteolin. $Luteolin-7-O-{eta}-D-glucuronopyranoside$ significantly decreased the size of the gastric lesions that had been induced by exposing the gastric mucosa to indomethacin. The malondialdehyde content, which is the end product of lipid peroxidation, was increased significantly after inducing of reflux esophagitis. The malondialdehyde content was decreased by $Luteolin-7-O-{eta}-D-glucuronopyranoside$ but not luteolin or omeprazole. $Luteolin-7-O-{eta}-D-glucuronopyranoside$ has a more potent antioxidative effect than luteolin. $Luteolin-7-O-{eta}-D-glucuronopyranoside$ is a promising drug for the treatment of reflux esophagitis and gastritis.