While working on the benthic polychaetous annelides from the Jiaozhou Bay (in Shandong), Wutong Bay(near Xiamen )and Dongshan Bay (in Fujian coast),a new species (Pilargiidae: Synelmis )was found. A total of 37 specimens were studied. Holotype and paratype of the new species are deposited in Institute of Oceanology, Academia Sinica. Description of the new species is as follows.