﻿AbstractPhysomerinusjiulongensissp. nov.is described from a series of overwintering individuals collected in decomposing wood at Jiulong National Wetland Park, East China. The new species is characterized and separated from related congeners by the unique form of the sexually dimorphic maxillary palpi, greatly swollen male metafemora, as well as by the shape of the genitalia of both sexes. A key to, and a distributional map of,Physomerinusspecies occurring in China and on the Ryukyu Islands, Japan is provided.