Permeabilization of the plasma membrane of Chinese hamster ovary cells by application of external electric field pulses can be described as a three step process of induction, expansion and annihilation of transient permeated structures. This phenomenon is associated to an increase in microvilli, density at the cell surface. In the case of cells into contact, the resealing of the permeated state can lead to the formation of polycaryons to which is associated to a reorganisation of microtubules into the cells. This observation shows an alteration of the cytoskeleton organization as a consequence of cell electropulsation. Annihilation of the permeated state depends on several physical parameters of the technique, but, in opposition to the two first steps of induction and expansion, it appears to be under the control of the cytoskeleton.These results suggest that microtubules play an important role in the process. Although it is still difficult to describe the exact role of the cytoskelteon in electropermeabilization, its interaction with plasma membrane makes it a candidate as a regulatory element.