Abstarct: Drought and water deficit is one of the most important factors in agricultural products lost in the world. Mycorrhizal fungi are known as bio fertilizers. In order to evaluate tolerance some Iranian grape cultivars, Shahroodi, Peikani and Keshmeshi, to drought stress in inoculated with mycorrhizal ,Glomus mosseae, and without inoculation, a factorial experiment baxsed on randomized complete block design with five replications was conducted in the College of Agriculture, Shahrood University, Iran. 100 g of mycorrhizal were used for each pot. Rooted cuttings transferred to pots in Feb for three months to stabilization irrigated normally and bushes were trained with single branch. After that, Water stress treatments were done for two months at three levels, irrigating at 80, 60 and 40 % of soil field capacity. After drought treatments, vegetative and physiological characters, and N, P and K elements in leaf were measured. The results showed that the number of leaves, fresh and dry weight of leaf, total weight significantly reduced by drought stress and some physiological characteristics such as Spad index, stomatal conductance, leaf relative water content, leaf area and leaf nitrogen was also reduce. The amount of leaf proline, potassium and phosphor was increased in three grape cultivars under drought. In Mycorrhizal inoculation treatments, the number of leaves, leaf fresh and dry weight, total weight, current shoot growth, root length, root dry weight, leaf area and the amount of leaf potassium was significantly increased. Spad index and stomatal conductance decrease by Mycorrhizal inoculation treatments. The three grape cultivars have a different reaction to drought stress. The result indicated the Shahroodi cultivar is better reacted with mycorrhiza in compared to the Keshmeshi and Peikani cultivars. Keshmeshi and Shahroodi cultivars with minimum variation in water deficient treatment show more tolerance than Peikani cultivar to drought stress. Shahroodi cultivar showed a better reaction with mycorrhizal inoculation.