Due to increasing demand for edible oils, oilseeds crop production is going to have a great importance. Among the oilseeds crops adapted to the climate condition of our country, safflower is a native plant species and has more tolerance to drought and salinity stress, making this crop more promising for oil production. In Isfahan province, safflower is grown in a relatively large area as the second crop after harvesting the small grains. In order to estimate the genetic parameters for some agronomic traits of safflower in early spring and summer planting dates, 27 genotypes of safflower were evaluated in a randomized complete block design with three replications in each of the planting dates at the Research Farm of Isfahan University of Technology in 2012. The results showed that in both planting dates, there were significant differences among the genotypes for all the studied traits. Also, combined analysis of variance showed that planting date had significant effect on all traits; however, days to flowering, days to 50% flowering, seed yield per plant and seed yield per unit area more affected by the planting date. The interaction effect between genotype and planting date was significant for all studied traits, except for seeds per capitulum and number of branches per plant. Correlation coefficients showed that, plant height, number of capitula per plant and seed weight had the highest correlation with grain yield in both planting dates. Among the yield components, seeds per capitulum and 1000-grain weight had the highest correlation with grain yield in the first and second planting date, respectively. Estimates of broad-sense heritability and genetic and phenotypic coefficients of variation indicate that there was genetic variation among the genotypes for most of the traits in both planting dates. Broad-sense heritability for all studied traits except grain yield per plant and grain yield per unit area in the second planting date was higher than that of in the first planting date. Results of stepwise regression for grain yield per plant in the first planting date showed that seed per capitulum, capitulum per plant and 1000-seeds weight entered into the model, respectively and totally explained 95 percent of the variation of this trait; however, in the second planting date, number of capitulum per plant, number of seeds per capitulum and 1000-seeds weight were entered into the model, respectively and accounted 89 percent of the variation. It can be concluded that seeds per capitulum and number of capitula per plant can be used as selection criteria for indirect selection to improve grain yield in both planting dates. Keywords : Safflower, Genetic parameters, Agronomic traits, Planting date