NOVELTY - Crushed gallnut and n-propyl alcohol are stirred, soaked and extracted. The obtained extract is filtered, and acidic catalyst (5-10 wt.%) is added to filtrate. The obtained mixture is heated, dissolved, cooled, and filtered to obtain crude propyl gallate. The crude propyl gallate crystals are added to reaction tank, dissolved using water, and active carbon is added to mixed solution. The mixture is decolorized, filtered, crystallized, filtered, washed, and dried. The material is dehydrated, and wet propyl gallate crystals are dried, to obtain propyl gallate product.    USE - Manufacture of propyl gallate used as medicine.    ADVANTAGE - The method economically provides propyl gallate having high yield and purity with reduced consumption of auxiliary materials without affecting the environment.    DETAILED DESCRIPTION - Impurities and iron from gallnut are removed, and crushed to 30-50 meshes. The crushed gallnut is added to an extraction tank, and n-propyl alcohol is added. The mixture in the extraction tank is stirred, soaked and extracted at room temperature for 4-6 hours. The content of n-propyl alcohol is 6-10 times with respect to weight of gallnut powder. The obtained extract is filtered, and obtained filtrate is added to a reaction tank. Active carbon (3-5 wt.%) and refined kieselguhr absorbent (5-10 wt.%) are added to the reaction tank, decolorized, and the absorbent is filtered. Acidic catalyst (5-10 wt.%) is added to the filtrate, reacted at 70-90 degrees C for 3-5 hours, cooled to room temperature, filtered and impurities are removed. The obtained mixture is depressurized and the filtrate is evaporated at 120 degrees C. N-propyl alcohol is recovered at several stages, and 5-10 times of water is added to the concentrate. The obtained mixture is heated, dissolved, cooled to 5-15 degrees C, crystallized for 5-8 hours, centrifuged and filtered to obtain crude propyl gallate. The crude propyl gallate crystals are added to the reaction tank, dissolved using 8-12 times of water at 60-90 degrees C, and 1-3 weight% of active carbon is added to the mixed solution. The mixture is decolorized, filtered, cooled to 5-15 degrees C, crystallized for 5-8 hours, centrifuged, filtered, dehydrated, and obtained material is washed using pure water until the pH is 6-7. The material is dehydrated for 1 hour, and the wet propyl gallate crystals are dried in a vacuum drier to obtain propyl gallate product.