A rabbit model of Yang deficiency was established by means of total thyrodectomy and the effect of Decoction for warming kidney and restoring Yang (DWKRY) on the hepatic ultrastructure of the model was observed under transmission eletron microscopy. It was shown in the liver cell of the rabbit model that the number of organelles was decreased, the mitochondria were reduced, degenerated and irregularly distributed, a large number of glycogen granules was stored in the cytoplasm, and the intercellular space was widened. After the administtration of DWKRY, the ultrastructure of liver cells approached normal. This study provides a valuable morphological basis for the establishment of Yang-deficiency animal model and the evaluation of the effect of DWKRY on Yang-deficiency syndrome.