［Objective］ A molecular -imprinted electrochemical sensor was developed to detect ceftiofur sodium in milk.［Methods］ Firstly,a molecular -imprinted film was prepared on the surface of a gold electrode by electropolymerization with ceftiofur sodium as a template molecule and acrylamide as a functional monomer in phosphate buffer solution.The electrochemical performance of the sensor was characterized by differential pulse voltammetry and cyclic voltammetry,and the construction parameters and detection conditions were optimized for the sensor.Under the optimal conditions,the sensor was used to quantitatively determine the content of ceftiofur sodium in milk.［Results］］ The sensor constructed under the optimal conditions exhibited a good linear detection range (1×10^-6~1×10^-4 mol/L ) for ceftiofur sodium,with a detection limit of 5×10^-7 mol/L and good selectivity and stability.In addition,milk samples were detected by the sensor,and the recovery rates of spiked milk samples were 78.0%~98.9%.［Conclusion］ The sensor is simple,rapid,cost -effective,and sensitive,and it can be used for the detection of ceftiofur sodium in real samples.