Abstract: Electrochemical behavior of 304L and S32304 stainless steel in phosphoric acid solution with different temperatures and concentrations by means of polarization curve and electrochemical impedance spectroscopy.Resultsshowed that with the increase of the phosphoric acid solution concentration,the corrosion voltage,the corrosion current and the polarization resistance of stainless steel increased.With the increase of the phosphoric acid solution temperature,the corrosion voltage and the corrosion current of the stainless steel increased and the polarization resistance and solution resistance decreased.Therefore,the corrosion-resistant properties of S32304 stainless steel are superior to that of 304L stainless steel.