Fluorescence spectrum is unique for each water sample, and is called “aqueous fingerprint”. Aqueous fingerprint could indicate the contamination in water and thus is a new technology for early warning. Cephalosporin is one of the most commonly used antibiotics worldwide yet with environmental hazards. The production of cephalosporin in China is growing every year. Therefore, the study of aqueous fingerprint of cephalosporin pharmaceutical wastewater is significantly important for both monitoring the discharge of pharmaceutical wastewater and protecting the aquatic environment. In this study we investigated the properties of water fingerprint of cephalosporin pharmaceutical wastewater. There existed 6 peaks in the fingerprints. According to the emission wavelength, these peaks could be divided into two groups: the first group included the peaks locating at excitation wavelength/emission wavelength of 230/350, 275/350, 315/350 nm and the second group consisted of the peaks locating at excitation wavelength/emission wavelength of 225/405, 275/410 and 330/420 nm respectively. The highest intensity was found at excitation wavelength/emission wavelength of 230/350 nm. In each group, the fluorescence intensity of the peaks with shorter excitation wavelength is higher. pH could significantly change the position and intensity of the peaks. When pH rose, the peak intensity of first group decreased and that of the second group increased. The intensity decrease is called fluorescence quenching and the intensity increase is called fluorescence sensitizing. The sensitizing and quenching was probably related to the fluorescence organic components with acid and alkaline radical groups in the wastewater. Because if a fluorescent substance contains weak acid or base groups, both the molecular configuration and ionic configurations exist in the solution at the same time. The spatial structure of these configurations are different. This makes the luminescent properties of the configurations different. When pH changes, the ratio of molecular configuration and ionic forms also changes, which causes the change of location and intensity of the fluorescence peaks. Above all, the properties of aqueous fingerprint of cephalosporin pharmaceutical wastewater is distinct and distinguishable. The properties of aqueous fingerprint can be used as a novel tool to identify the appearance of cephalosporin pharmaceutical wastewater.