In oblique unidirectional and multidirectional wave fields, wave overtopping on a seawall which is covered with wave-dissipating blocks and which protects land area with corner parts geometrically is investigated with conducting horizontally two-dimensional physical model tests.
　At the corner part the multidirectional waves cause more overtopping rate than the unidirectional waves, depending on wave incident angle. This feature is affected by component waves of multidirectional waves normally incident upon the seawall as well as diffracted waves generated at the corner part. Oblique multidirectional waves make less reduction of overtopping rate than the oblique unidirectional waves. In a range of wave incident angle, the oblique multidirectional waves cause more overtopping rate than the unidirectional waves even on a straight part of the seawall.
　The results on the physical model tests under the unidirectional wave action show that the wave-dissipating blocks at the end part of seawall where the waves acts on the side of blocks are easily movable. In the area where waves overtop severely on the seawall, the blocks on a crown part of wave-absorbing work is also movable easily.