The purpose of this study was to obtain some microscopic investigations in fibrosis of bovine livers infected by fasciola Hepatica. Totally 28 livers of which 22 with fascioliosis and 6 normal livers were examined. In the livers with fascioliosis, it was seen that the fibrous tissue increased between lobules iri the portal areas. In this tissue, the collegen fibrae were found abundantly. In the livers with fascioliosis, bile canaliculi were dilated, the number of hematocytes were decreased but diamaters of their nuclei were bigger than those of normal livers hepatocytes. A large number of polyploidy nuclei were seen in infected hepatocytes of livers.