Abstract: This article reports a new species of Cyathocotyle appeared in the pasture duck′s caecum in Fujian.Features of this ovoid fluke,which was 1.175-2.375 mm×0.950-1.875 mm in size,included an obvious oral sucker and pharynx with one large holdfast,two testes varying in shape,few eggs,and one near-round ovary and long,bag-shaped cirrus pouch in the back of the fluke mainly in the caecum of some domestic ducks.Compared with similar Cyathocotyles,this fluke had distinguished characteristics,thus named Cyathocotyle caecumalis sp.nov.The epidemiology,clinical symptoms and pathological changes are briefly described with regards to the possible disease caused by Cyathocotyle caecumalis sp.nov.