Abstract: This paper is aimed at researching the cathodic protection parameters of 907A under alternately immersion circumstance.The potentiodynamic polarization curves were measured to evaluate their electrochemical properties under free corrosion and traditional cathodic protection conditions.The results revealed that the corrosion character of alternately immersion condition is serious than that of continuous immersion condition.The cathodic potential of 907A under alternately immersion circumstance should be more negative than the traditional cathodic potential,which is-0.85V_CSE,the feasible potential is-0.90V_CSE.