Abstract: A simple and sensitive fluorimetric method has been developed for the determination of trace palladium with N-（1-naphthyl）ethylene diamine（NPED） as a fluorescence reagent.The method is based on the complex formation between Pd（Ⅱ） and NPED at pH 4.0 with fluorescence quenching of NPED.The calibration curve is linear over the Pd（Ⅱ） concentration range of 5.0×10^-7～6.0×10^-6?mol/L,with a detection limit of 3.8×10^-7?mol/L.Platinum（Ⅳ） and other diverse metal ions do not disturb with Pd（Ⅱ） determination.The proposed method has been applied to the determination of Pd（Ⅱ） in palladium-containing catalysts and water samples with satisfactory results.