NOVELTY - A vaccarin monomer is prepared by (A) extracting raw materials, (B) enriching by macroporous resin, (C) preparing and liquid phase separating, and (D) recovering product. The step A comprises crushing vaccariae semen into coarse powder, adding 8-10 times water, boiling for 2 hours, filtering and 3 times extracting, combining extract solution, and cooling to room temperature. The step D comprises absorbing vaccarin by activated AB-8 macroporous resin column at 2-5 BV speed, rinsing, condensing rinsing solution, drying and obtaining vaccarin monomer product.    USE - Method for preparation of vaccarin monomer (claimed).    ADVANTAGE - The method has simple and rapid method, low solvent consumption and high yield. It is environment-friendly and can obtain plenty of products at a time.    DETAILED DESCRIPTION - Vaccarin monomer is prepared by (A) extracting raw materials, (B) enriching by macroporous resin, (C) preparing and liquid phase separating, and (D) recovering product. The step A comprises crushing vaccariae semen into coarse powder, adding 8-10 times water, boiling for 2 hours, filtering and 3 times extracting, combining extract solution, and cooling to room temperature. The step (B) comprises absorbing cooled extract solution by activated AB-8 macroporous adsorbent resin at speed of 2-5 bed volume (BV), and respectively rinsing impurities using 3 times water and 2 times 30% ethanol; and rinsing target substance by 2 times 50% ethanol solution, collecting rinsing solution and condensing to 10% of original volume. The step C comprises filtering condensed solution by microporous filter film of 0.45 mu m, separating by effective chromatographic column to obtain vaccarin solution, and recovering organic solvent to obtain vaccarin solution. The step D comprises absorbing vaccarin by activated AB-8 macroporous resin column at 2-5 BV speed, rinsing by 2 times 95% ethanol, condensing rinsing solution, drying for 6 hours at 80 degrees C and obtaining vaccarin monomer product.