Abstract: On a graphene decorated glass carbon electrode, the cinnamic acid imprinted electrochemical sensor has been prepared by a molecularly imprinted electropolymerization route using O-phenylenediamine as functional monomer and cinnamic acid as template molecule, respectively. The optimizations on membrane formation conditions and current responding to template molecule have been carried out. Electrochemical performances of cinnamic acid imprinted electrochemical sensor have been studied by cyclic voltammetry（CV）, square wave voltammetry（SWV） and electrochemical impedance spectroscopy（EIS） using potassium ferricyanide as probe. Surface morphology of imprinted membrane is observed by scanning electron microscope（SEM）. The as-prepared sensor is used to detect the concentration of cinnamic acid aqueous solution, and the results are presented as follows: The sensor has a good linear relationship between peak current and logarithm of cinnamic acid concentration in the range from 8×10^-8 to 5×10^-3 mol·L^-1, and the correlation coefficient R and detection limit can come to 0.9992 and 2.7×10^-8 mol·L^-1, respectively. The electrochemical sensor with recover rates of 95%-106% can be used to detect cinnamic acid in water, showing good detection performance.