Abstract: Using immersion test with weight-loss method, EDS and SEM to analyze the electrochemical properties, corrosion rate, corrosion morphology and corrosion products. The corrosion behavior of S32304 duplex stainless steel in 85% industrial phosphoric acid solution was studied at different temperatures. The results show that S32304 duplex stainless steel possessed a good resistance to corrosion in 85% industrial phosphoric acid solution at temperatures below 85 ℃, the corrosion increasesed with the increase of temperature in the temperatures range. The corrosion performance got worse obviously at temperatures above 55 ℃.