NOVELTY - Composite microbial inoculums comprise 10-20 pts. wt. Bacillus subtilis, 20-30 pts. wt. B.mucilaginosus, 50-70 pts. wt. B.licheniformis, 5-15 pts. wt. sodium humate, 30-50 pts. wt. bran, 30-50 pts. wt. rice bran and 5-15 pts. wt. seaweed.    USE - The composite microbial inoculums are useful for preparing complex microbial fertilizer (claimed), improving granular structure of soil, and stimulating growth of crops.    ADVANTAGE - The composite microbial inoculums increase yield of crops.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for method for preparing the composite microbial inoculums, which involves (a) preparing B.subtilis deposit by test tube slant storing method, expanding and connecting the deposit to fresh test tube beef extract peptone medium and culturing at 30 degrees C for 2-4 days using incubator, (b) inoculating the strain deposit into culture solution, where the culture solution is prepared by 5 g beef extract, 5 g peptone, 5 g sodium chloride and 1000 ml water, and has pH of 7.2, adding the culture solution into container, sterilizing the container, culturing the container in shaking incubator until bacterial liquid number reaches to more than 2000 billions/ml to obtain seed culture, and fermenting the seed liquid based on volume of single stage fermentation tank, where the inoculum size is 0.1-10%, (c) preparing the fermented liquor by 10 kg starch, 10 kg soybean cake powder, 1 kg peptone, 1 kg ammonium sulfate, 0.5 kg monopotassium phosphate, 0.1 kg yeast powder, and 5 kg calcium carbonate, adjusting pH value to 7.5, sterilizing the fermented liquor using high pressure steam, cooling sterilized fermented liquor to 20-30 degrees C by circulation cooling water, maintaining tank at positive pressure, and gage pressure of 0.05 MPa, pressing the seed liquid into fermentation tank by differential-pressure method, and controlling the pressure to 0.05 MPa and temperature of 28 degrees C, (d) after finishing the single stage fermentation, pressing the bacterial liquid into two stage fermentation tank by pipeline, where the culturing condition is same as single stage fermentation, when the fermentation liquor reaches to mass index of pH of 5.5-6, the bacterial number of the fermented liquor is 2000 billion/ml and spore ratio is 80%, and adding the fermented liquor into a sterile liquid storage tank, (e) preparing B.mucilaginosus deposit and B.licheniformis deposit by performing steps (a)-(d), (e) uniformly mixing the liquor and controlling moisture content to not greater than 20%, where the viable count is not greater than 2000 billions/g, and (f) mixing the fermented liquids.