NOVELTY - Preparation of organic selenium nutrient solution includes selecting disease-free and fresh grapes, cutting off top buds, washing with water, spin-drying, crushing, and extracting with ethanol through Soxhlet extractor; placing healthy and disease-free eel into water, opening cloacal orifice, cutting its tail, dropping blood into circular dish, and mixing with extract; covering with gauze, adjusting pH with sodium sulfite solution when mixture generates mold, and washing mold until mold fully grown; and inoculating with solid medium, incubating until spores are formed and adding sterile water.    USE - Method for preparation of organic selenium nutrient solution (claimed).    ADVANTAGE - The nutrient solution does not contain other harmful impurities and increases grapes selenium content by more than 90% or 3.5-8.5 mu g/g.    DETAILED DESCRIPTION - Preparation of organic selenium nutrient solution comprises:    (A) selecting disease-free and fresh grapes, cutting off top buds, washing with water, spin-drying at speed of 250 revolutions/minute until surface has no more dripping water, and crushing into size of 1.2x 1.2 cm or less;    (B) loading into filter cartridge, feeding into Soxhlet extractor, connecting extractor into collection bottle, adding collection bottle with 2/3 volumes of ethanol, and condense-refluxing for 8-12 hours to obtain extract;    (C) placing healthy and disease-free eel into water for 2-3 days without feeding to remove body impurities, opening cloacal orifice at 0.8-1.2 cm, cutting its tail, dropping blood into 5 cm circular dish to disinfect, stop dropping when blood thickness is 1.8-2.2 mm, and mixing with extract;    (D) covering with gauze, and setting temperature to 25-32 degrees C and air relative humidity to 65-70% for 5-8 days;    (E) adjusting pH to 5.5-6.2 using 1.2 mol/L sodium sulfite solution when mixture generates mold, and washing mold once every other day until mold is fully grown;    (F) inoculating with solid medium, incubating to 25 degrees C for 7-10 days until spores are formed, adding with sterile water to obtain suspension, inoculating with seed culture medium, culturing to 27 degrees C for 22-24 hours under sterile air condition while stirring to obtain seed culture broth, inoculating with phenylacetic acid precursor-containing medium through fermenter, fermenting to 26 degrees C for 7 days under sterile air condition while stirring, cooling fermentation broth, filtering, adjusting pH to 2-2.5 using 0.2 mol/L hydrochloric acid solution, multistage countercurrent extracting with butyl acetate, decolorizing with activated carbon, and distilling; and    (G) storing at 20-25 degrees C in dark atmosphere.