© 2018 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria.In this study, a novel carbon paste electrode was prepared using the salt form of polyaniline (pani)-activated carbon composite sensitive to phenol. Polyphenol oxidase enzyme was immobilized to the modified carbon paste electrode by cross-linking with glutaraldehyde. The amperometric determination is based on the electrochemical reduction of o-quinone generated in the enzymatic reaction of phenol at -0.15 V vs. Ag/AgCl. The effects of pH and temperature were investigated and optimum values were found to be 8.0 and 45 °C, respectively. The linear working range of the electrode was 1.0×10-6 - 5.0×10-5 M, R2 =0.9819. The storage stability and operation stability of the enzyme electrode were also studied.