<正> Evidence so far accumulated suggests that the human early placenta can be considered as a complicated neuroendocrine organt. Our previous reports have demonstrated that the human early placenta presents not only a variety of neuropeptides but also neurotransmitters such as 5-hydroxytryptamine (5-HT), dopamine (DA) and norepinephrine (NE). It has been shown that these neurotransmitters in human placenta may play an important role in the process of blastocyst implantation and maintenance of normal pregnancy. As far as we are aware, no information concerning the DA and/or NE receptors localized in the