Blood AFP and HPL of normal pregnant women were detectable at the end of the 3rd month of gestation, increased with the number of months of gestation reached the peak at around the end of the 9th month and leveled off or tended to fall off thereafter ; after delivery, AFP decreased to about half the level at delivery on the 5th puerperal day, while HPL was undetectable two hours after delivery. Umbilical arterial blood AFP showed higher levels than maternal blood AFP, and a good correlation was seen. Umbilical arterial HPL showed lower levels than maternal blood HPL, and here there was no correlation. Blood AFP and HPL of pregnant women showed no diurnal variations. Blood AFP of pregnant women showed high levels in cases of intrauterine fetal death and twin pregnancy, while HPL showed low levels in cases of intrauterine fetal death and high levels in twin pregnancy. Both AFP and HPL were within the normal limits in cases of an anencephalic, Rh(o) negative and diabetic pregnant women. In hydatidiform mole, both AFP and HPL were undetectable.