By using a kind of molecular wire diphenylacetylene as the modifier and the binder,a new carbon paste electrode,which was denoted as carbon molecular wire electrode(CMWE),was prepared and used as the substrate electrode.Then graphene(GR) was electrodeposited on the surface of CMWE to get the modified electrode named as GR/CMWE.The electrochemical behaviors of dopamine(DA) on GR/CMWE were investigated by cyclic voltammetric method.A pair of the well-defined redox peaks were observed.Compared with that of CMWE,the redox peak currents increased greatly with the decrease of the peak-to-peak difference,indicating that the electrode reaction of DA on GR/CMWE was reversible.Under the optimal conditions,the peak currents had a good linear relationship with DA concentration in the range of 8.0×10-7 – 2.0×10-3 mol/L with a detection limit(3σ) of 2.55×10-7 mol/L.The commonly coexisting substances did not interfere DA detection, and the proposed method was applied in the determination of DA in injection samples with satisfactory results.