Abstract: A novel polydopamine functionalized reduced graphene oxide/gold (PDA-RGO/Au) nanocomposite modified electrode was fabricated, and applied for electrochemically determine dopamine. UV-vis spectroscopy and FTIR characterizations confirm the successful reduction of graphene oxide (GO) to RGO during the dopamine self-polymerization process. Then, Au nanoparticles with average size of 120 nm were electrodeposited onto the PDA-RGO film modified glassy carbon electrode (GCE) was performed. The electrocatalytic activity of the PDA-RGO/Au modified GCE was evaluated by oxidation of dopamine using cyclic voltammetry and linear sweep voltammograms. The results showed that the obtained anodic peak currents were linearly proportional to concentration in the range of 0.01 mM to 1 mM with a detection limit of 6.237 μM (S/N = 3.0). In addition, the effect of co-existing species such as ascorbic acid, uric acid and glucose on the determination of dopamine was investigated. Therefore, the PDA-RGO/Au modified dopamine sensor with excellent sensitivity and selectivity could provide an idea matrix for clinic applications.