NOVELTY - Bio-organic complex fertilizer comprises (in parts weight) organic material containing amino acid (50-75), humic acid complex fertilizer (15-35), bone powder (5-15), effective microorganism (EM) strain (0.05-1) and auxiliaries (0.05-1), and has effective viable count of not less than 2 millions/g, organic mass of not less than 25 wt.%, nutrient mass of not less than 10 wt.%, moisture content of not greater than 30 wt.%, and pH of 5-8.5.    USE - Bio-organic complex fertilizer.    ADVANTAGE - The bio-organic complex fertilizer is environmental-friendly, and improves the yield and quality of crop fields.    DETAILED DESCRIPTION - Bio-organic complex fertilizer comprises (in parts weight): organic material containing amino acid (50-75), humic acid complex fertilizer (15-35), bone powder (5-15), EM microorganism strain (0.05-1), and other auxiliaries (0.05-1), where the organic material containing amino acid is chosen from dry residues of extract of Chinese drug or methane dry slag, humic acid complex fertilizer comprising ammonium humate, potassium humate and humic calcium phosphate, the EM microorganism strain is chosen from actinomycetes, nitrogen fixing bacteria, phosphorus bacteria, silicate Bacillus mucilaginosus, mycorrhiza and yeast, which are not mutually antagonist, and auxiliaries include humic acid and one or more chosen from urea, ammonium carbonate, calcium superphosphate, ammonium phosphate and concentrated superphosphate. The bio-organic complex fertilizer has effective viable count of not less than 2 millions/g, organic mass of not less than 25 wt.%, nutrient mass of not less than 10 wt.%, moisture content of not greater than 30 wt.%, and pH of 5-8.5. The bio-organic complex fertilizer is prepared by (a) weighing the organic material containing amino acid, humic acid complex fertilizer and bone powder, mixing the components, crushing and agitating the mixture uniformly, (b) fermenting the mixture using EM microorganism strain, and inoculating a portion of fermented mixture to raw material obtained in the step (a), regulating the moisture 45-55 wt.%, adding the auxiliaries, and regulating the pH to 5-6 and the ratio of carbon to nitrogen to 25:1, pilling obtained fermented product into a strip stack-like of 1 mm long, and controlling the temperature at 50-65 degrees C, and fermenting the mixture for 15-20 days, (c) fermenting the mixture second time using the pile obtained in step (b), and EM microorganism strain for 5-7 days at normal temperature, and (d) drying and sieving the fermented product, regulating pH and moisture of the obtained product, and pilling the obtained product to bio-organic complex fertilizer. An INDEPENDENT CLAIM is included for preparation of the bio-organic complex fertilizer obtained by the above-mentioned method.