Abstract: It was reported that a ternary coordination complex was formed among Eu(Ⅲ),pefloxacin and EDTA,and due to the intramolecular energy transfer of the coordination complex,characteristic fluorescence spectra of Eu(Ⅲ) were observed at the peaks of 579 nm,592 nm and 615 nm,when excited at 278 nm. Based on these facts,a method for rapid determination of pefloxacin (PEFX) by fluorophotometry was proposed,using wavelengths of 278 nm and 615 nm as the excitation and emission wavelength respectively. Linearity range was found in the range of 0.02-1.40 mg of PEFX per liter,and detection limit obtained was 0.02 mg·L-1. Recovery tests were made,and the values of recovery obtained were in the range of 96.8%-100.7%.