The retrohepatic segment of inferior vena cava and the ostia venae hepaticae entering into it have been studied in 60 human normal adult livers.Ostium vena hepatica is averaged 8.2±0.43 in number per liver

varied from 4 to 18

and large

middle and small sized orificies can be classi- fied.Middle and/or the large ostia which positioned below the second porta hepatis were seen in 57 cases(95.0%)

most of them being presented at the left anterior and lower one-fourth portions of the wall of inferior vena cava.The latter portion is the more important one

because not only the largest lower large orifice but also several differently named hepatic veins may be exposed in this sector at a dissection.On this account

it should be treated reasonably as the third porta hepatis. In this paper

we reported concomitantly the mean value of the long diameter of ostia venae hepaticae

the angle made de by the hepatic veins with the inferior vena cava and those with the sagittal plane. Retrohepatic segment of inferior vena cava are curved leftward in 75.00±5.59% of cases.It’s length measured 7.11±0.18 em

and in 6.67±3.22% it is encircled by a band of hepatic tissue constituting the tunnel of inferior vena cava. Some aspects concerned the fundamental concept and clinical application of hepatic veins are discussed

the importance of lower large orificies is stressed.