in order to investigate the effect of inoculation with mycorrhizl fungi on the grain yield and gas exchange of barley cultivars in rainfed conditions, a field experiment was carried out in factorial arrangment using randomized complete block design with three replications at the farm station of Sarablah Agricultural Research Center during 2019-2020 cropping season. Experimental treatments including factor of barley cultivars (Mahali, Mahoor, Khoram and Fardan) and fertilizer sources treatment including: control (without fertilizer source), 50% P fertilizer, mycorrhizal fungus (Glomus mosseae, Glomus etunicatum and Rhizophagus irregularis), mycorrhizal fungi + 50% P chemical fertilizer and 100% P chemical fertilizer. The results of this study showed that the interaction effect of cultivar ×fertilizer sources were significant on dry matter remobilization efficiency from spike, Contribution of spike reserves to grain yield, dry matter remobilization efficiency from stem, contribution of stem reserves to grain yield, current photosynthesis rate, contribution of current photosynthesis and grain filling rate. So that the interaction betwen Fardan cultivar× mycorrhizal fungi + 50% P chemical fertilizer had the highest dry matter remobilization effeciency from spike, contribution of spike reserves to grain yield, current photosynthesis rate, contribution of current photosynthesis and grain filling rate. In this study, the highest dry matter remobilization effeciency from stem, contribution of stem reserves to grain yield was obtained from the interaction of Mahali cultivar×control treatment.