This study was performed to investigate the antimicrobial effects of the Citrus unshiu Markovich extracts against food-borne pathogens. First, the Citrus unshiu Markovich was extracted with methanol at room tempetsture, and fractionation of the methanol extracts from Citrus unshiu Markovich was carried out by using petroleum ether, chloroform, ethyl acetate, and methanol. The antimicrobial activity of the Citrus unshiu Markovich extracts was determined using the paper disc method against food-borne pathogens and food spoilage bacteria. The ethyl acetate extracts ofCitrus unshiu Markovich showed the highest antimicrobial activity against Bacillus cereus and Shigella sonnei. A synergistic effect was found in combined extracts of Citrus unshiu Markovich and ffedyotis diffusa Willd as compared to each extract alone.Finally. the growth inhibition curve was determined using ethyl acetate extracts of Citrus unshiu Markovich against Bacillus cereus and Shigella simnel. The ethyl acetate extract of Citrus unshiu Markovich showed strong antimicrobial activity against Bacillus cereus at due concentration of 5,000 ppm. The 5.000 ppm of ethyl acetate extract from Citrus unshiu Markovich retarded the growth of Bacillus cereus more than 24 hours and Shigella sonnet up to 24 hours. The ethyl acetate extracts of Citrus unshiu Markovich have shown an antimicrobial effect against Bacillus cereus and Shigella sonnei.