Abstract: A new catalytic fluorimetric method for the determination of trace cefoperazone sodium has been developed. The method is based on the catalytic effect of cefoperazone sodium on the oxidation of K₂S₂O₈ with lucigenin in NaOH medium. The detection limit(S/N=3) is 6.95 mg /L and the linear range of determination is 7.56～55.44 mg /L . The proposed method is simple 、speediness and credibility . The method has been applied to the determination of cefoperazone sodium in injection.