The present work aimed to investigate the microscopic and ultramicro-scopic structure of the liver to assess the level of hepatic impairment during preg-nancy toxemia. Seven pregnant smal-tailed Han sheep of negative urine ketone bodies were assessed in this study. Toxemia was induced by limiting food and movement late in pregnancy. Three sheep developed obvious clinical symptoms with motor weakness, depression, anorexia, locomotion disturbances, blindness and lan-guishment. We harvested their liver tissues as pathological material, and used rou-tine histological and electronic microscopy methods to observe the histopathological changes in smal-tailed Han sheep induced by pregnancy toxemia. Autopsy of the livers of the sheep revealed deep yel ow coloration, intumescence and hemorrhage on the surface. Microstructural features indicated fatty degeneration, which is a main characteristic of fatty liver. Hepatocel ular ultrastructural changes were observed un-der an electronic microscope. The characteristic findings were nucleolus concentra-tion, vacuolation of mitochondria and excessive glycogen granules in the cytoplasm. Via this experimental protocol, pregnancy toxemia of sheep was successful y in-duced, providing a pathological model for the study of this disease. After the experi-mental induction of pregnancy toxemia, the clinical symptoms of pathogenic sheep and pathological changes to their livers exhibited obvious characteristics of pregnan-cy toxemia.