Abstract: Background and Objective: Daibaijie (DBJ) is Chinese name of Dregea sinensis Hemsl. Traditionally it is used for treatment of various diseases. The objective of study was to determine the gastroprotective effect of DBJ against aspirin-induced gastric ulcers. Methodology: In this research 60 Sprague Dawley (SD) rats were divided into 6 groups. Water was provided to normal and negative groups, omeprazole (20 mg kg–1) to positive group and DBJ extract (1, 2 and 3 g kg–1) to low, middle and high dose groups, respectively as pre-treatment. After 1 h of pre-treatment, aspirin (250 mg kg–1) were administered to all groups except normal group. Above scheduled treatments were provided continuously for 2 weeks. After 2 weeks, rats were sacrificed. The pH plus acidity, Gastric Wall Mucus (GWM), ulcer index, histological assessment, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), myeloperoxidase (MPO), prostaglandin E2 (PGE2) and protein concentration were examined. Moreover, all the data were statistically analyzed by one way ANOVA, followed by student’s t-test to compare different groups. Results: The DBJ showed a dose-dependent (60.11-84.34%) protection, while omeprazole showed (82.74%) protection. In addition, DBJ also considerably increased (p<0.01) the pH and reduced the acidity of gastric contents. Gastric levels of antioxidant enzymes SOD, CAT, GSH-Px were markedly enhanced while MDA level and MPO activity significantly reduced (p<0.001) by DBJ. Furthermore, DBJ also increased the PGE2 level and mucus production. Conclusion: It is concluded from results, that DBJ extract has great potential to prevent stomach ulcers. The gastroprotective effect might be associated to increase in PGE2 to produce mucus and inhibition of neutrophil infiltration due to decrease in MPO activity.