Abstract :
Oak tree (Quercus persica) is a native plant genus in some areas of Iran, spatially in the western and the northwestern regions. This tree is a rich source of phenolic compounds such as gallic acid andtannin. Phenolic compounds present in spice plants as dietary sources possess bioactive properties protecting cellular systems against oxidative stress.For identification of Gentisic acid (2,5-dihydroxybenzoic acid) in cupule of oak, cupules were harvested from a random sample of plants in 3 replications In Lorestan province then put in bags and dries in shadow. Extract was thickener by using Rotary apparatus. Finally, determination and identification of Gentisic acid was by High-performance liquid chromatography (HPLC) method.