Epidermis was separated from the dermis through blister formation by the application of negative pressure on the surface of human skin. The im- pedance of the blistered epidermis was tested by a skin impedance detec- tor. It was found that the low impedance characteristics of the line of latent propagating sensation along the channel on the epidermis still exist as before the formatjon of blisters. Experiments were carried out on the channel of pericardium of normal persons and on the channels of stomach and spleen of excised limbs after amputation. The preliminary experiments show that the low impedance nature of the line of latent propagating sensation along the channel is intimately related with the structure of epidermis.