A novel electrode based on graphitic carbon nitride and nafion modified glassy carbon electrode was fabricated.The modified electrode was used to determine cadmium（Ⅱ） in acetate buffer solutions.The factors for determination of Cd2+,including graphitic carbon nitride amount,pH value,potential and time for pre-concentration were optimized.Under the optimum conditions（pH 4.5,deposition potential:-1.2 V,accumulation time:5 min,amount of modifier:10 μL）,the stripping peak currents of Cd2+ were linear in the concentration range of 1.0×10-7-1.4×10-5 mol/L,and the linear equation is I（μA）=8.03 c（μmol/L）-2.00,r=0.998 5.The detection limit（3σ） was 3.3×10-8 mol/L.The modified electrode showed an excellent anti-interference property,and common inorganic ions had no effect on the determination of cadmium.The modified electrode was successfully applied in the determination of Cd2+ in tap water with recoveries of 98.8%-99.6%.