By means of indirect immunofluorescent method vasopressin localization has been defined in neurons of the locus coeruleus, in terminals, converging to the substantia nigra cells and the sylvian aqueduct area, as well as in the granule-containing cells of the human cerebral blood vessels. The granule-containing cells are identified as melanocytes, when investigated by comparative light-optic and electron microscopical technique. The melanocytes of the cerebral vessels have various size and form in accordance to their different functional state. In some melanocytes peptide vesicles are revealed. This demonstrates a possible synthesis of vasopressin. It is supposed that local endocrine regulation of the cerebral hemocirculation is performed by cooperation of granule-containing cells, producing hormones with oppositely++ directed constrictor and dilatator action to the vessels.