In order to know more about the cytoskeletal structure around the bile canaliculi of hepatocytes, we used the following procedure. Liver specimens were passed through an 18-, a 21- and then a 23-gauge needle, by which they turned into cylindrical or oval blocks of 0.4 mm in diameter. Because of their small size, the cytosolic ground substances of every hepatocyte were washed out clearly after subsequent treatment with the solution containing 0.5% Triton X-100 and 0.5 mg/ml saponin for 15 min. This short-term extraction preserved both the cytoskeleton and the plasma membrane of the hypatocyte quite well, and we could observe the crossbridge filaments connecting between a core bundle of microfilaments and plasma membrane of the microvilli of the bile canaliculi.