The auther studied on alternation of permeability of cell-membranes by electric current and reached to the following results. 1) Plasmolysis of epithelial cells of Tradescantia virginica by hypertonic solution (0.5-1.0%) of sodium chloride will be stopped at the neighbourhood of the cathode by passing through of the electric current. 2) In the neighbourhood of cathode potassium-ions escape from the cells into the surrounding medium. It will be so understanded that the damage of semipermeability of the cell-membranes allows passage of anion and potassium-ion escapes in balance of it. Same thing occurs on the muscle cutaneus dorsi of frog. 3) Potassium-escape can be observed on the resting muscle of frog when the temperature of bathing fluid exceeds 29-32°C.