Abstract: Limnotrachelobdella sinensis and Limnotrachelobdella taimeni have already been recorded in China. The former is widely distributed in freshwater bodies of Central China and has harmful effects on common carp and crucian carp. The latter is chiefly distributed in the Heilongjiang Basin.Four specimens of a limnotrachelobdellid leech were taken from marine fish caught from Bohai Sea (Qin Huang-tao) and Yellow Sea (Tsingtao) and identified as Limnotrachelobdella okae Moore, 1924. This species has not been previously described in China Seas and, thus, Ⅰ give a description on its internal and external features, especially the male and female reproductive systems.In addition, two specimens belonging to same species were taken from the fins of a marine fish, Epinephelus akaara in South China Sea (Xiamen). It is considered to be new to science.