A rutin electrochemical sensor was developed by electrodepositing copper nanoparticles on a glassy carbon electrode modified with multi walled carbon nanotubes(MWNTs)-Nafion.The electrochemical performance of the sensor was investigated by cyclic voltammetry and electrochemical impedance spectroscopy in potassium ferricyanide-potassium ferrocyanide system.The morphology of the sensor was studied by scanning electron microscopy,and differential pulse voltammetry was used for the detection of rutin.Results showed that the sensor had a good catalytic effect on rutin.Under the optimized conditions,the linear range of the sensor for rutin was from 1.0×10-8 mol/L to 1.0×10-6 mol/L,with a detection limit of 8.4×10-9 mol/L(S/N=3) and recoveries of 98.1%-101%.With the advantages of simple fabrication,wide linear range and high sensitivity,the sensor provided a new and effective method for the determination of rutin in Flos Sophorae Immaturus and other samples.