Affiliation of seed size with germination rate and percentage, seedling emergence rate and percentage, 50% mean emergence time, cumulative emergence rate, through 4 Safflower cultivars (Isfahan, Goldasht, Padideh, and Sina), in three different sizes of seed, were investigated under two separate experimental conditions in the field and laboratory of Seed and Plant Certification and Registration Institute Karaj-Iran, during 2008 to 2010. Both experiments were conducted in a factorial arrangement based on randomized complete block design, with three replications. The field results showed that cultivars Goldasht and Padideh were superior compare to other cultivars and large seeds with the highest seedling emergence rate, 1000-SW, and seed yield were superior to control and small. In the laboratory, morphological traits consisted of germination percentage, fresh and dry weight of root and shoot were significantly different, so that cultivars Goldasht and padideh with large seeds displayed better reaction. Thus, due to display better performance by cultivars Goldasht and Padideh, also creating vigorous seedlings by large seeds, using cultivars with adequate food storage as well as selecting large seeds with more germination potential to obtain higher yield and good plant establishment should take into consideration. Key words: Cultivar, Goldasht, mean germination time, morphological traits, vigorous seedling.