Abstract.-Here is proposed a new Quercus rotundifolia Lam. forest association, silicicolous, upper mesomediterranean to supramediterranean, subhumid to humid, present in the « Estrelense, Toledano-tagano et Galaico-português » sectors, with a edaphoxerophilous character, named Teucrio salviastri-Quercetum rotundfoliae ass. nov. Their floristic, ecologic and dynamic particularities are exposed. It's also presented a comparison with the others holm-oak communities described in the Paeonio broteroi-Quercenion rotundifoliae Rivas-Martínez in Rivas-Martínez, Costa & Izco 1986 sub-alliance and ecologically present in the meso-and supramediterranean bioclimatic levels.