NOVELTY - Microbial preparation obtaining involves taking water from water body and culturing water by using beef extract-peptone-agar culture medium having pH value 8.2-8.4. Bacteria are separated from water by plate separation method and the formed colony is purified continuously for three times. The purified strains are dyed and Clostridium perfringens is separated with metachromatic granules and Gram negative bacteria. Two strains with better effect of purifying water body are selected by removal rate experiment of chemical oxygen demand (COD), nitrogen and phosphorus present in wastewater.    USE - Method for obtaining microbial preparation (claimed) for purifying water and for bioremediation of rivers, reservoirs, ponds, lakes and other sewages.    ADVANTAGE - The microbial preparation obtaining method is cost-effective, convenient, and provides microbial preparation with quick flocculating and discoloring effect, and effectively removes nitrates, ammonia and soluble phosphorus and reduces COD of water.    DETAILED DESCRIPTION - Microbial preparation obtaining involves taking water from water body and culturing water by using beef extract-peptone-agar culture medium having pH value 8.2-8.4. Bacteria are separated from water by plate separation method and the formed colony is purified continuously for three times. The purified strains are dyed and Clostridium perfringens is separated with metachromatic granules and Gram negative bacteria. Two strains with better effect of purifying water body are selected by removal rate experiment of chemical oxygen demand (COD), nitrogen and phosphorus present in wastewater. The suspended substances and azo dye are flocculated and discolored. Both obtained strains are inoculated in thick liquid culture medium in a shaker and are cultured for 10-24 hours at 35-38 degrees C at a speed of 100-120 revolutions per minute (rpm). A bacterial suspension is prepared, which has a strain concentration of 100000000 per ml. Both prepared bacterial suspensions are uniformly mixed to obtain a microbial preparation having a strain concentration of 100000000 per ml.