Safflower is an important oilseed crop with high oil quality, relatively high tolerance to drought, salt and winter cold which is native to Iran and has specific importance for oilseed production. The most important aim of the present study was to evaluate agronomic traits and identification of more drought tolerant populations in eight F4 populations of safflower derived crosses between Carthamus tinctorius , C. oxyacanthus and C. palaestinus . The experiment was performed during 1392-1393 in the research farm of Isfahan University of technology, in two drought stress and non-stress environments. A 15*15 lattice design with 2 replications was used in each environment to evaluate 119 f4 families according with 3 parental lines and 3 pure lines. The results indicated that the range of stem production did not have high heritability in non-stress condition and had lower heritability under stress conditions relative to other traits. The results of analysis of variance indicated that environment had not significant effect but the effect of genotype and the variation between populations was significant for most of the important traits, which means the existence of high variation among the genotypes and populations. Genotype*environment interaction was only significant for 5 important yield-related traits (number of fertile heads, total number of heads in plant, seed yield, number of seeds per head and ratio of fertile/infertile heads). Results of mean comparisons indicated that in stress and non-stress conditions, pure line (PL) population was desirable and IO (from the cross of C. tinctorius × C. oxyacanthus ) was undesirable populations. PO ( C . oxyacanthus × C . palaestimus ) was a population with high plant height and IO was a dwarf population under stress and non-stress conditions. C. tinctorius was a high-yield with high height species and C. oxyacantha was a low-yield dwarf species. Results of correlation analysis in non-stress environment indicated no significant correlation between head diameter/head height, stem diameter and 100-seed weight with most of the traits; however, in drought stress conditions, these correlations were significant. Cluster analysis under non-stress and stress conditions divided the genotypes into two and five groups, respectively. Principal component analysis under non-stress condition indicated that the first and second components explained 54% of the variation. The first and the second components were named as “yield index” and “economic index”, respectively. Under stress condition, the first and second components explained 53% of the variation and they were named as “yield index” and “economic index”, respectively. The related biplot in non-stress condition, confirmed the results of cluster analysis. The results of path analysis under stress and non-stress environments indicated that the stem flowering first height had the most direct positive effect and total numbers of head in plant had the most direct negative effect on yield. Tolerance and susceptibility indices including MP, GMP, YI, STI and DI had significant positive correlations with yield under stress conditions. Key words: safflower, drought stress, interspecific crosse