A new compound, 2-boronobenzaldehyde-(2′-hydroxyl-4′-sulfonic acid) naphthalene hydrazone (1), was synthesized and its structure was characterized by proton nuclear magnetic resonance, mass and element analyses. The presence of Pb 2+ led 1 to undergo colorimetric and fluorescent changes, which were detectable with the naked eye. Thus, a dual spectral response for Pb 2+ detection was introduced. In KH 2 PO 4 –NaOH buffer aqueous solution (pH 6.0), 1 exhibited fluorescence enhancement at 568nm and hyperchromicity at 595nm upon the addition of Pb 2+ . The fluorescent intensity change was proportionate to the concentration of Pb 2+ with a dynamic working range of 5.0×10 −7 molL −1 to 1.0×10 −4 molL −1 and a detection limit of 3.7×10 −8 molL −1 . The fluorometric method was successfully applied for the detection of Pb 2+ water of Qianhu Lake and soil in Nanchang university campus. The recoveries were 111–116% for water and 97.6% for soil respectively, determined via the standard addition method.