Silicone rubber, Flexicast (Nisshiri Corp., Tokyo) colored with four different dyes (acrylic polymer emulsion) was injected into the bile duct, hepatic artery, portal vein and hepatic vein. The liver parenchyma was corroded with potassium hydroxide solution. Because the liver cast with Flexicast had adequate flexibility, it was possible to observe the inner structure of the liver by separating the hindering small branches with the fingers. The three vascular systems and duct system were clearly distinguished by their different colors. Peripheral branches were easily removed with a scissors, if necessary, to expose the main branches. The details of the method for the corrosion preparation of the liver with Flexicast were described and discussed.