Extraction-spectrophotometric method for determination of lomefloxacin is proposed.The ion pairs complex of lomefloxacin with brornocresol green (BMG) can be extracted into CHCI3 at pH 3.6 and has absorption maximum at 415nm.The calibrationgraphs generated was linear over the range of 1～15mg/L drug in solution (r=0.9997).ε=2.5×104L·mol-1·cm-1.The detection limit is 0.014mg/L.The recovery of method is 98.9%～101.6%.The proposed method has been successfully applied to the determination of lomefloxacin in pharmaceutical formulations.