Drought stress is one of the most important environmental stresses that in many parts of the world and especially in arid areas reduces crop production. Among the seed oils adaptable to Iran’s climate, safflower ( Carthamus tinctorius L.) has a special place and is adapted to areas with water shortages. This experiment was conducted to evaluate drought tolerance of 64 safflower genotypes using of simple lattice design in two moisture regimes of non-stress and stress in the Agricultural Research Farm, Isfahan University of technology 2011-2012 in Lavark; Najaf Abad. In this study, morphological, phenological and agronomic traits including number of days to flowering, days to 50% flowering, days to maturity, reproductive period, plant height, number of branches (main branches), thousand seeds weight, number of seeds per head, number of heads per plant, seed yield per plant, seed yield per hectare, biological yield per hectare and harvest index were evaluated. Results of combined analysis variance of the two moisture conditions revealed that drought stress is reduced significantly all traits. Moreover, results of analysis of variance based on simple lattice design showed that genotypes differed significantly for all traits under non- stress conditions except number of branches, number of heads per plant and harvest index.in other hand in moisture stress conditions genotypes varied significantly for all the studied traits. Result of relationships analyse among traits using stepwise regression and path analysis at two moisture conditios showed that three traits number of heads per plant, number of seeds per head and 1000 seed weight, respectively, are of greater contributions in the determination of seed yield per hectare, that can be used to indirectly select for grain yield in breeding programs. Based on the cluster analysis of 64 genotypes in two mosture conditions of non-stressed and stressed, genotypes, were divided in to 4 and 3 grou respectively. In this study, drought tolerance index (STI) and geometric mean of productivity (GMP) were known as the superior indicator of drought toleancer. Based on STI index genotypes PI-258417, S6-697-307, PI-198844, 34-14-73, Kurdistan-47 and Kurdistan-5 were suggesed as safflower drought tolerant genotypes. Key word: Safflower, Drought stress, Seed Yield, Drought tolerance index .