An electrochemical sensor based on graphene sheets（GS） and gold nano-particles（Au） composite nano-particles modified screen-printed carbon electrodes（SPCEs） was fabricated（SPCEs│GS/Au）,and an electrochemical method was developed for the determination of trace cadmium（Cd） in water by differential pulse stripping voltammetric（DPSV）method.Au preparation and the construction processes of SPCEs│GS/Au electrode were characterized by scanning electron micrography（SEM）,and the electrochemical properties of Cd2+ were investigated.Under the optimum conditions,a good linear relationship was obtained between peak current and Cd2+ concentration in the range of 2.5×10-7-2.5×10-5 g/L（r2=0.998 0） with a detection limit（3σ） of 1.8×10-7 g/L.The method was applied in the determination of Cd2+ concentration in real water samples with recoveries of 96%-107%.The analytical results were consistent with those of the graphite furnace atomic absorption spectrometric（GF-AAS） method.The SPCEs│GS/Au electrode showed a high response current and an enrichment ability due to the modification of composite nano-particles.Therefore,the electrode was suitable for the determination of Cd2+ in water with advantages of disposable design,little sample consumption and simple operation.