The present invention relates to a wave dissipation block provided to a breakwater for protecting the coast against incident waves coming from the open sea to the seashore, thereby reducing reflective waves generated from the breakwater and the height of the incident waves, the wave dissipation block comprising: a block main body having a polygonal column; a plurality of entases protruding separately from each of vertical surfaces, which form the block main body, and having a protrusion width, which gradually increases toward the center of the block main body; and a plurality of radial legs extending along the protrusion direction with respect to each of the entases so as to be interlocked with the legs of other wave dissipation blocks while forming radial legs around the center of the block main body.