NOVELTY - Extracting glucoside A from Dolichos falcata root or leaf, involves (a) obtaining D.falcata root or leaf as raw material, reflowing, extracting, and filtering to obtain the D.falcata extract solution, (b) decompressing and recycling product, preparing medicinal liquid, adding medicinal liquid in macroporous adsorption resin column, eluting the liquid, washing the column, collecting the eluent, and condensing and drying the eluent to obtain the D.falcata glycoside A.    USE - The method (M1) is useful for extracting glucoside A from D.falcata root or leaf. The method (M2) is useful for extracting total saponin from D.falcata. The glucoside A and total saponin, or their hydrolyzed product, salt or derivative are useful for preparing immune-inflammation resistant drugs for treating rheumatoid arthritis or gouty arthritis (all claimed).    DETAILED DESCRIPTION - Method (M1) for extracting glucoside A from Dolichos falcata root or leaf, involves (a) obtaining D.falcata root or leaf as raw material, adding 6-10 times of alcohol aqueous solution to the D.falcata, reflowing and extracting for 12 times, and filtering to obtain the D.falcata extract solution, (b) decompressing and recycling the alcohol until there is no alcohol taste, adding water or alcohol (30 vol.%) to the obtained product, preparing medicinal liquid, where each ml of medicinal liquid contains 0.1-2 g D.falcata extract, adjusting pH value of the medicinal liquid to 4-6 using hydrochloric acid or sodium chloride 1-2 mol/l, adding the obtained medicinal liquid in macroporous adsorption resin column, eluting the medicinal liquid based on the weight, washing the column using alcohol aqueous solution, collecting the eluent, and condensing and drying the eluent to obtain the D.falcata glycoside A. INDEPENDENT CLAIMS are included for the following: (1) method (M2) for extracting total saponin from D.falcata, involves obtaining D.falcata traditional Chinese medicinal material, adding 6-10 times of alcohol aqueous solution to D.falcata, reflowing and extracting for 12 times at room temperature, filtering the extract to obtain filtrate, decompressing and recycling alcohol until there is no alcohol taste, and drying the obtained product; and (2) glucoside A derivative of formula (I).    R=2-4C alkyl.