A specimen of Blachea xenobranchialis Karrer and Smith, 1980 newly collected from Taiwan water represents the first record of the species, as well the genus, in the northwestern Pacific Ocean. A detail description and the color photos are provided. Our specimen agrees with the type series of B. xenobranchialis, except for the greater dorsal- and anal- fin rays, a relatively small preanal and trunk length, a relatively wider interorbital space, a relatively narrow postorbital space, and a relatively small gill opening. These differences may attribute to the individual variations, which are discussed.