Abstract: Carbon dots(CDs)were firstly prepared via a simple pyrolysis route using citric acid as the carbon precursor and glycine as modifier. The obtained CDs were further purified by n-butyl alcohol, which made the particle size more uniform and the fluorescence intensity stronger. When excited at 380 nm, the maximum emission wavelength of the CDs was about 480 nm, with a quantum yield of 47%. Based on fluorescence quenching, a novel method for chloramphenicol assay was developed with glycine-passivated CDs. This method is simple and rapid. A linear relationship between the change of fluorescence intensity and the concentration of chloramphenicol was obtained with a relation coefficient of 0. 999 7. The recovery was in the range of 99% to 101% with a relative standard deviation of 0. 3%, which shows CDs′ potential application in drug detection.