Tetraclinis articulata is an essence of great socio-economic value. The development of the resistance and survival potential of this species to sometimes extreme environmental conditions are a concern of the managers. for that, the present work is fixed as an objective to evaluate the rate of mycorrhization of thuya roots and to highlight the diversity of arbuscular mycorrhizal fungi (AMF) of thuya from two sites (Beni Souhane and Aderj) of the region of Sefrou (Middle Eastern Atlas). The results obtained showed that the thuya roots carry different structures of endomycorrhizal fungi. The frequencies of mycorrhization of the roots are of the order of 93.3% at the level of site Aderj and 80% at Beni Souhane. The mycorrhizal root intensities are respectively 45.8% and 40% for the Beni Souhane and Aderj sites. Moreover, the arbuscule contents are 26.05% in Beni Souhane and 25.52% in Aderj. The vesicle contents are 14.89% in Aderj and 21.51% in Beni Souhane. The density of endomycorrhizal spores in the rhizosphere of Thuya is 98 and 26 spores / 100 g of soil, respectively in Beni Souhane and Aderj. The identification of isolated spores allowed to note the presence of 37 species belonging to 7 genera, 7 families and 3 orders. The genus Glomus is the most abundant, with a distribution percentage of 63.5%. The species richness is 29 taxa in the site of Beni Souhane and 18 species at the level of Aderj. Besides, the thuya of the Beni Souhane site shows a better rate of mycorrhization of roots and a mycorrhizal species richness greater than that of the Aderj site. This is reflected on the state of forest formation that is coming well to Beni Souhane. It would, therefore, be valuable to develop inocula from the endomycorrhizal fungi present in the Thuya rhizosphere and proceed to controlled mycorrhization in nurseries to obtain resistant and vigorous plants.