NOVELTY - Biological treatment method of marine dredged soil or coast sludge, involves adding water to microorganism mixture (BM-S-1) (KCTC 11789BP), rice bran, powdered peat moss, waste wood mushrooms, rice husk powder, molasses and salt, mixing the materials, maintaining the mixture to obtain microbial liquid, mixing e.g. bran, powdered peat moss and waste wood mushrooms to obtain raw material mixture, inoculating microbial liquid to raw material mixture, culturing, drying, culturing the microorganism microbial agent stock solution, and treating concentrated mixture.    USE - The method is useful for biological treatment of marine dredged soil or coast sludge (claimed).    DETAILED DESCRIPTION - Biological treatment method of marine dredged soil or coast sludge, involves adding 100 pts. wt. water to 0.05-1 pts. wt. microorganism mixture (BM-S-1) (KCTC 11789BP), 0.125-0.15 pts. wt. rice bran, 0.05-0.075 pts. wt. powdered peat moss, 0.05-0.075 pts. wt. waste wood mushrooms, 0.175-0.21 pts. wt. rice husk powder, 0.015-0.025 pts. wt. molasses and 0.01-0.05 pts. wt. salt, mixing the materials, maintaining the mixture at 15-28 degrees C to obtain microbial liquid, mixing 70-72.8 pts. wt. bran, 28.5-35.7 pts. wt. powdered peat moss, 28.5-47.47 pts. wt. waste wood mushrooms, 100 pts. wt. rice husk powder, 8.57-28.5 pts. wt. molasses and 0.02-0.11 pts. wt. salt with respect to 100 pts. wt. microbial liquid to obtain raw material mixture, inoculating 0.05-1 pts. wt. microbial liquid to raw material mixture at 85-95 degrees C, culturing the mixture, drying cultured mixture to obtain powder, culturing the microorganism microbial agent stock solution to the liquid state to produce a stock solution, and treating concentrated mixture. INDEPENDENT CLAIMS are included for the following:    (1) microbial agent comprising microorganism mixture (BM-S-1) (KCTC 11789BP), rice bran, powdered peat moss, waste wood mushrooms, rice husk powder, molasses and salt; and    (2) self digestion process of marine dredged soil or coast sludge, involves adding microorganism preparation of separated precipitate by marine or coastal dredged sludge containing the organic material into organic material to volume of collecting tank to decompose organic material, mixing 10-20 wt.% organic material and 80-90 wt.% microbial agent to induce self digestion process.