An optical approach was developed for the detection of Cd2+ based on ion imprinted polymer membrances as sensing receptors.The polymer was synthesized with cadmium ions as a template and 2-naphthyl acrylate as both the fluorescence tag and a complex-forming agent.The free radical polymerization was performed within PVDF films and was initiated by 2,2′-azobisisobutyronitrile at 65 ℃ in dimethyl sulfoxide.The polymer showed a high selectivity for cadmium ions.The calibration curve was linear over the Cd2+ concentration range of 1-9 μmol/L with a detection limit of 5.5×10-7 mol/L.Compared with that by the ICP-MS method，the results by this method had no obvisous difference.The RSDs（n=10） of the polymer for Cd2+ was 2.3%，and the recoveries for Cd2+ in spiked river water were in the range of 97%-100%.