Safflower ( Carthamus tinctorius L.), from the composite family, is an oilseed crop which adapted to the Iran's climate conditions. Due to the trend of increasing arid areas in the country, identification of tolerant cultivars is important. In this regard, the best strategy for identifying water stress tolerant plants is to investigate the plant's abilities in physiological, morphological and anatomical changes to tolerate environmental stress. The present study aims at assessing and identifying 40 safflower genotypes for improving and improving the oil content under water stress condition, assessing the correlation of physiological traits with each other and with oil content as well as grouping genotypes based on genetic variation in terms of physiological and biochemical traits under the conditions. Water shortage tensions have been implemented. This study was conducted in spring and summer of 1396 in a research and experimental farm of Isfahan University of Technology arranged in a completely randomized block design with four replications. In this project, two different levels of irrigation control and water stress were investigated. According to the results of combined analysis of variance, the effect of drought stress on the most of measured traits was significant. Significant variation between and within the groups obtained from cluster analysis in non-stress conditions indicates relatively high germplasm of safflower genotypes present in this study, which can be used for the development of oily seeds. The genotypes that were placed in the first group in cluster analysis in the first group were subjected to stress in other groups, indicating different responses of different genotypes after water deficit stress in terms of oil content. However, the AC-Sunset and A2 genotypes of Canadian and Iranian origin under stress conditions were similar to non-stress conditions in the group that had the highest oil content and the lowest fiber content, which can be proposed for an increase in oil content. Iranian and foreign genotypes from different parts of the world in cluster analysis and decomposition to the main coordinates were not based on the physiological traits measured in the Keywords : Drought stress, Safflower, Fiber content, Oil content, Genetic diversity