There are presented data about morpho-physiological changes, as well as physiologico biochemicals, which appear in the tissue of potato tubers infested with Ditylenchus destructor (phases 2, 3 ditylenchose). The obtained data confirms that, D. destructor in the nutrition process eliminates in parallel celulosolitic and pectolytic enzymes, which cause complete maceration of the pectocellulosic membranes of the infected potato cell, as well as the parenchymal cortical tissue in which predominantly cellulose and pectic substances , dominating being cellulose. The results of the biochemical analyzes revealed that, at this stage in the parasite tissue there is a diminishing of the dry mass quantity, and the increase of the quantity of water. It is important to mention that in the plasmalemma mechanically traumatized by the nematode stiletto, the main intracellular inclusions of the potato tuber - the starch granules - were kept without change. Subsequently, when plasmalemma is destroyed, the granules diffuse into the nematode suspension.