The effect of Hippophae rhamnoides (HR) extract on oxidative damage on rat's gastric tissue depending on co-implementation of methotrexate (MTX) and indomethacin (IND) was investigated biochemically and histopathologically. HR extract was given to HR extract-given (HRIM) group of rats with dose of 50 mg/kg, and to IND+MTX-implemented rat group (IMG) orally with distilled water through catheter. One hour after, IND and MTX combination was given to HRIM and IMG groups orally for 7 days with dose of 5 mg/kg. In gastric tissues of IMG group, the MDA amount increased to healthy-sham (SG) and HRIM groups. The amount of tGSH, in IMG group's gastric tissue decreased to SG and HRIM groups. Serious focal erosions, sub-mucosal edemas and mixed-type inflammatory cell infiltrations have been observed on surface epithelium of histopathological sections of stomachs of IMG group. HR extract prevent the gastric damage in rats' gastric tissues, which was formed by MTX and IND combination.