While continuing the series of research into various aspects of human placental tissue during bilateral perfusion of after birth cotyledon in vitro, the authors made an attempt to evaluate the production of alpha hCG and beta hCG. The research was done by modified Schneider procedure. Nine experiments were carried out in different cotyledons, in each case during 120 minutes. The authors found the content of alpha hCG in mother extracorporeal circulation (M) 105.5 +/- 76.8 ng/ml, whereas in fetal circulation (F) 2.6 +/- 1.5 ng/ml. Beta hCG was found only in mother circulation and it amounted to 0.9 +/- 0.4 ng/ml. The content of beta hCG in foetal circulation in all time intervals was 0 ng/ml. Basing on their own research the authors presume that placental tissue during bilateral perfusion in vitro preserves functional activity as to the hormone examined during 120 minutes of experiment.