The corrosion process was analyzed for carbon steel when used in Ca(ClO)2 hypochlorite Disinfection Solution. The corrosion resistance of Ni-P electroless coating was characterized by electrochemistry method. From the results, it was shown that the corrosion reaction can occur spontaneously according to the caculation result. The corrosion products existing on the carbon steel surface were loose and porous. The main conpositions of the products are about iron oxide. For Ni-P coatings, the corrosion current densities reduced gradually with the increasing of electroless plating time.