Four species of the genus Platorchestia Bousfield are described from Taiwan, e.g., P. pacifica n. sp., P. joi Stock and Biembaum, 1994, P. japonica (Tattersall,l922) and P. humicola (Martens, 1868). The former two species, together with P. platensis (Kmyer, 1845) and P. munmui Jo, 1988, compose a closely related species cluster. P. pacifica n. sp. was found on almost all the coast of the mainland and neighboring islands in Taiwan, while the other three species were found in the mainland north of23.5°N.