Abstract: The cork oak forests of Theniet-El-Had Wilaya Tissemssilt (west of Algéria) form an integral part of the territory of the National Park. They are situated mainly in the south side of the park to a maximum altitude of 1575 m. This work consists of a study on the current state of the cork oak forests abandoned for decades. The methodology is to install during 2012 circular plots of 5 acres surface. In total 23 units are installed environmental samples exposure, altitude, topography and slope) and dendrometric (circumference, total height) are harvested. The trees have an average height rarely exceeding 8 m and an average thickness of 0.70 m. The stands have a very low regeneration and irregular structure characterized by a poor distribution of stems, the result of a long absence of appropriate silvicultural treatments. In addition almost 80% of inventoried stems are not harvested (the last operation dates back to 1994). The rehabilitation of the cork oak forests of Theniet El Had based on a thorough knowledge on tree growth factor and its variability (typology of stands and fertility index) and cork’s productivity.