The corrosion survey of Yomogawa Sluice at Amagasaki Harbor has been carried out, and the following results were obtained.
　It was confirmed that there was such corrosion tendency that corrosion was concentrated on the projecting portion of sluice, i.e. edges of vertical, across or diagonal beams, directly under L.W.L., whilie their corrosion rates in thickness direction were small. On the other hand, on the jet pipe concentrated corrosion was generated on the steel portions connecting with mud or floatages. And the concentrated corrosion phenomena mentioned adove can be explained from point of view of macro-corrosion.
　Furthermore, data on corrosion survey method of lock gate or sluice type facilities, which has not been yet standardized, were obatained.