11 species of Didymozoidae are found from marine fishes in the East China Sea, during 1975, 1976, 1979, Besides 5 known species, viz. Did ymozoon biranus Ku el. Shen, 1965，Didymozoon priacanthi Ku et Shen, 1965, Syncorpozon hainanesis Ku et Shen, 1965, Didymozoon pneumatophori Gu et Shen, 1983 and Nematobothrium filiforme Yamaguti, 1934. 3 species are record for the first time from China, namely, Didymocystis soleiformis Ishii, 1935, Didymocystis bifurcata Yamaguti, 1970, Colocyntotrema auxis Yamaguti, 1951, 1 genus and 3 species are described as new. all the measurements are in mm excepting ova in μ. The type specimens are deposited in the Institute of Oceanology, Academia Sinica, Qingdao, China. The descriptions of the new genus and species are given below.