A glassy carbon electrode(GCE) modified with nafion-DTPA (diethylene triamine-pentaacetic acid)-glycerol is used for the highly selective and sensitive determination of a trace amount of Cu(II). Various experimental parameters, which influenced the response of nafion-DTPA-glycerol modified electrode to Cu(II), are optimized. The Copper(II) is accumulated on the electrode surface by the formation of the complex in an open circuit, and the resulting surface is characterized by medium exchange, electrochemical reduction, and differential pulse voltammetry(DPV). The electrochemical response is evaluated with respect to concentration of modifier, pH and preconcentration time, quiet time, copper(II) concentration, and other variables. A linear range is obtained in the concentration range 1.0${ imes}$10$^{-8}$ M-1.0${ imes}$10$^{-6}$ MCu(II) with 7 min preconcentration time. The detection limit(3s) is as low as 2.36${ imes}$10$^{-8}$ M (1.50 ppb).