Abstract: Chitosan (CTs)-polyaniline (PANI) composite coatings were prepared on the surface of 304 stainless steel by electrochemical synthesis. The surface morphology, chemical composition and crystal structure of the composite coatings were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The anticorrosion properties of CTs-PANI composite coatings were investigated by polarization curves and electrochemical impedance spectra. The results show that the 10%CTs-PANI composite coating had the best corrosion resistance in 3.5% (mass fraction) NaCl solution. After 168 h immersion in 3.5% NaCl solution, the corrosion current density of the 10% CTS-PANI composite coating reduced by about 2 orders of magnitude compared with 304 stainless steel, and the corrosion potential positively shifted close to 500 mV. The composite coatings had an excellent protective effect on substrate materials.