A pot experiment was conducted at collage of agriculure of Isfahan University of Technology, Isfahan, Iran, in order to evaluate the effects of inoculation with two species arbuscular mycorrhizal fungi ( Rhizophagus intraradices and Funneliformis mosseae ) and foliar application of four concentrations of ascorbic acid (0, 60, 120 and 180 mg/l in irrigation water) on barley plants under three salinity levels (0, 75 and 150 mM NaCl). Treatments were arranged as factorial based on a completely randomized design with four replications. Salinity decreased mycorrhizal infection, phosphorous and potassium concentrations, relative water content, membrane stability index, chlorophyll and carotenoid concentrations, plant height, root volume, shoot and root dry weights, number of spikes per plant, number of grains per spike, number of grains per plant, 1000 grain weight and grain grain weight per plant, while increased the concentration of sodium and proline, the activities of antioxidant enzymes including catalase, peroxidase and ascorbate peroxidase, H 2 O 2 and lipid peroxidation (MDA content), chlorophyll a/b and shoot/root dry weight ratio. The reductions at salinity levels of 75 and 150 mM NaCl in shoot dry weight were 20 and 47% and in grain weight per plant were 28 and 62%, respectively. The extent of increase in the activity of peroxidase due to salinity was greater than those of catalase and ascorbate peroxidase. Mycorrhizal inoculation increased phosphorous, potassium and proline concentrations, the activities of antioxidant enzymes, plant growth characteristics and grain weight per plant while decreased the concentrations of sodium, MDA and H 2 O 2 . In some traits, the effects of inoculation by F. mosseae were greater as compared to those of Gh. Intraradices . However, the differences between the two mycorrhiza species in terms of their effects on biomass production and grain weight were not significant. The inoculation of plants by Gh. intraradices and F. mosseae increased shoot dry weight by 11 and 13% and grain weight per plant by 13 and 14%, respectively. Under non-saline condition the extents of increases in biomass and grain weight due to inoculation were greater in the plants inoculated by Gh. intraradices but under saline condition the increases were greater in the plants inoculated by F. mosseae . The extent of increase in the activity of ascorbate peroxidase due to inoculation was greater than those of catalase and peroxidase. The application of 60, 120 and 180 mg/l of ascorbic acid increased shoot dry weight by 9, 17 and 14% and grain weight per plant by 6, 13 and 11%, respectively. The highest biomass and grain weight per plant under all salinity levels were obtained in the plants sprayed by 120 mg/l ascorbic acid. Howevere, the differences between 120 and 180 mg/l ascorbic acid concentrations were no significant in this regards. The magnitudes of increases in biomass and grain weight per plant due to application of 60 and 120 mg/l ascorbic acid were greater under high salinity leval as compared to non-saline condition. The interaction between mycorrhiza and ascorbic acid were not significant on biomass and grain weight per plant and also on most of measured traits. Based on the results of this experiment, mycorrhizal inoculation and foliar application of ascorbic acid improved plant growth but the extent of positive effects of these amending factors depended on the level of imposed salinity. Key words: Barley, Salinity, Mycorrhiza, Intraradices, Mosseae, Ascorbic acid