The mycorrhization of Pinushalepensis had been investigating dusing different autochthonous ectomycorrhizal (ECM) fungi isolated from soils collected at the Haouz region. The obtained results showed that Hebelomamesophaeum, Suillusbellini, Suilluscollinitus, the isolate 3530 of Suillusmediterraneensis and Tricholomaterreumhas led to growth improvements depending on the fungal speciesand the nature of phosphate (P) source. The culture of Aleppo pine seedlings in the presence of organic (phytate) or mineral (KH2PO4) P source is reflected by a very significant increase of acid phosphatase activity in cytoplasmic and membrane-bound fractions. This phosphatase induction was found to be more important in the presence of organic phosphate. In the presence of phytate, a positive correlation was observed between high levels of phosphatase activity and the improvement of growth and P nutrition of mycorrhized Aleppo pine seedlings.