This paper presents research on the influence of water potential of potato tuber tissue on the mechanical parameters and count sum of the acoustic emission signal. In the experiment method of acoustic emission have been used. The results obtained prove the influence of water potential on the formation and propagation of cracks in the plant tissue deformed with a constant velocity along the sample axis. It has been observed that an increase in water potential causes a decrease in the compressive strength, maximal strain, critical strain, critical stress and an increase in the total count sum.