The immunocytological work revealed that in amphibia beta-endorphin is distributed in embryonic epidermis during development with prominent expression at late tail bud stage which coincides with the stage of epidermal conductivity of full strength. To see whether any relationship exists between the presence of beta-endorphin and the epidermal conductivity of amphibian embryos, naloxone of 1 and 2 mumol/L was used. It has been demonstrated that after 45-60 minutes in the naloxone solution the embryonic epidermal conductivity disappeared and 90-120 minutes after the beginning of naloxone treatment the epidermal conductivity was again recovered. It was suggested that the opiate peptides, such as beta-endorphin, play some role in the epidermal conductivity of amphibian embryos.