Using a low temperature resin Lowicryl K4M and post-embedding immunogold labeling, localization of actin and cytokeratin was examined in hepatocytes and biliary epithelial cells in normal human livers. Preservation of the liver tissues was satisfactory at the electron microscopic level. In immunolabeling of actin, gold particles were mainly found on microvilli and around the junctional complexes and at cell borders in the hepatocytes as well as biliary epithelial cells. In immunolabeling of cytokeratin, the gold particles were rather preferentially found in the perinuclear cytoplasm and around the junctional complexes in the biliary epithelial cells and hepatocytes. These particles were mainly found to be located on the intermediate filaments at higher magnification, although a considerable number of intermediate filaments were not labeled in the hepatocytes and biliary epithelial cells. Double straining method using the gold particles of different sizes clearly confirmed the abovementioned distribution of actin and cytokeratin in the same cells. From these observations, it was suggested that post-embedding immunoelectron microscopy using Lowicryl K4M is a useful tool for analysis of cytoskeletal organization in the liver tissue.