A generic diagnosis of family Eucodoniidae is revised, with the monotype genus Eucodonium. Three new species, Eucodonium bitentaculatum Xu, Huang & Guo, sp. nov., E. brevistyle Xu, Huang & Lin, sp. nov. and E. longitentaculatum Xu, Huang & Wang, sp. nov. from South China Sea are described and illustrated. A key to all species of Eucodonium is provided. The type specimens are deposited in the Third Institute of Oceanography, State Oceanic Administration.