Hemicultersp. and Cultrichthys eJythropteroswere recorded firstly as the second intermediet host of small liver fluke (Clonorchis sinensis) in Vietnam. This study was conducted during April to September 2012 with the aim to investigate occurrence of liver fluke Metacercariae (Clonorchis sinensis) in Gia Vien district, Ninh Binh province. Total of 771 fish of 5 species including Hemicultersp. (419), Carassius carassius (236 fish), Squaliobarbus curriculus (53 fish), Anabas testudineus (47 fish) and Cutrichthys eJythropteros (16 fish) were collected at Gian Khaufish market, Gia Vien district. Collected samples were packed in cool box and transported to Research Institute for Aquaculture No.1 based in Dinh Bang, Tu Son, Bac Ninh for Metacercariae isolation and idenification. Pepsin digestion method was used to isolate Metacercariae from fish tissue. The key to identification from Sohn et all, 2009 and experimental infection from Kay et all, 2009 were used to identify and confirm liver fluke (C. sinensis). Result has shown there are 2 fish species infected with C. sinensis with 21.95 percent and 0.98 metacercariae/fish in Hemiculter sp.
43.75 percent and 0.42 metacercariae/fish in Cutrichthys eJythropteros. Study also indicated that there is seasonal pattern changes in prevalence and intensity of C. sinensis metacercariae in fish.