Pancreas fluke worm (Eurytrema spp) normally parasitizes in the ruminants such as buffalo, cattle, goat, etc... In this study, the authors have used the primer set (E-18S - F: 5' GGC TCA TTA AAT CAG CTA TGG TT- 3' and E-18S-R: 5' ACG ACT TTT ACT TCC TCT AAA T 3') to amplify and to analyze sequence of the rrnS gene of Eurytrema spp. The size of sequence of rrnS gene was 1800 bp. The nucleotide sequence of rrnS gene in pancreas fluke worm identified in Viet Nam was similar up to 98.76 - 99.19 percent with those identified from pancreas fluke worm in China.