Abstract: Fluorescence properties of CDs (including fluorescence mechanism, excitation light/acidity dependence, chemical stability, resistance to photobleaching and upconversion fluorescence) and synthetic methods (including hydrothermal synthesis, solvent hot method, ultrasonic oscillation and microwave digestion) were reviewed. The focus was placed on the discussion of its application in the food safety testing, including heavy metal ions, legal and illegal food additives, pesticides and veterinary drug residues, food nutrition and pathogen detection, and the development trend was prospected for CDs (86 ref. cited).