The corrosion surveys at Center Pier (steel sheet piles), Shiogama Harbor, Quay Wall No.3 (steel sheet piles and tie rods), Fushiki Harbor and Suma Landing Bridge (pipe piles) have been carried out, and the following results were obtained.
　Corrosion tendency (b) was generated at Center pier, Shiogama Harbor, and corrosion rates of the flat portion of convex steel sheet piles directly under L.W.L.were 0.19 to 0.22 mm/yr.
　Corrosion tendency of steel sheet piles at Quay Wall No.3, Fushiki Harbor was (b), and corrosion rates of the flat portion of convex steel sheet piles directly under L.W.L. were 0.10 to 0.13mm/yr.
　It is supposed that corrosion tendency of steel sheet piles at Fushiki Harbor depended conciderably on the presence of fresh water.
　And besides, tie rod buried for 37 years at Quay Wall No.3, Fushiki Harbor did almost not corrode. And the corrosion rates of steel piles of Suma Landing Bridge were less than 0.05 mm/yr.