The most effective microbial strains with the best ability to reduce complex odor were isolated from earthworm and activated sludge and identified using a 16S rDNA method. The isolated strains, Staphylococcus cohnii HYC3 and S. carnosus JYC-4, were inoculated into the odor vials that had been left for 48 hours in water containing sesame dregs, and after 3 days, the ammonia was reduced to 5 ppm and 3 ppm from the initial 25 ppm, respectively. Complex odor was reduced to 2.5 and 2.2, respectively, while the control group maintained an odor of 5. The isolates were grown in the order of 30oC > 40 oC > 20 oC > 10 oC. For HYC-3 and JYC-4, the optimum pH was 7 and 10, respectively, and the strains grew well at neutral pH ranges. To monitor the amount of microorganisms remaining in the environment by using the strain as a preparation for odor reduction, a probe for real-time PCR was designed. Through the quantitative and sensitivity tests on the developed strains, it was found that they showed excellent sensitivity. Keywords: Complex odor, Livestock environment, Odor reducing microorganisms