The author pursued the changes of portal pressures and closed venous capillary pressures in normal dogs and in the normal dogs with experimental liver disturbances induced by allyl formate and carbontetrachloride and at the same time studied the picture of intrahepatic portal and intrahepatic venous capillaries by X-rays, and obtained the following results. 1. The portal pressures in normal dogs show the maximum of 120 mm H(2)O and the minimum of 70 mm H(2)O with average of 93 mm H(2)O, and the pressures of closed hepatic venous capillaries show the maximum of 136 mm H(2)O and the minimum of 95 mm H(2)O, with the average of 118 mm H(2)O. In the roentgenograms intrahepatic venous and portal capillaries can be traced to their fine ends as they flow in slow curves. 2. In the observations conducted at the interval of every 30 minutes for 5-6 hours after subcutaneous injection of 0.04 cc/kg allyl formate both portal pressure and closed hepatic venous pressure shew a marked rise, reaching their maximum one and half to two and half hours after the injection, thereafter showing a decreasing tendency. In the roentgengrams of intrahepatic veins and portal the shadow of blood vessels is poor and especially the direction of peripheral capillaries is indistinct. 3. In the observations conducted for 5-6 hours after the subcutaneous injection of 2.0 cc/kg carbon tetrachloride, both portal pressure and pressure of closed hepatic venous capillaries, rising graudally, reach the maximum three or three and half hours after the injection, thereafter showing a falling tendency. The roentgenograms of intrahepatic veins and portal veins show irregular or nodular blood flow and the decrease in the number of venous branches. 4. After subcutaneous injections of 0.01 cc/kg allyl formate or 0.3 cc/kg carbon tetrachloride per day successively for five days and measuring the portal pressures and pressure of closed hepatic veins on the sixth day, both show higher values than in the case given one single acute injection of a large dose. Roentgenograms of intrahepatic veins and portal veins reveal the nodular uneven direction of vessels markedly and irregularly. 5. Braching of intrahepatic venous capillaries and portal veins both present almost the same findings in their roentgenegrams.