Due to study the effect of planting date and seed priming on phenological stages, yield and yield components of sunflower varieties, an experiment was done as split factorial in the basis of randomized complete blocks design in 3 replications in research center of semnan (Shahrood). Planting date (20 Jun, 4 July and 19 July) as main plots and sunflower varieties (Azargol and Farah) and Seed priming methods (Osmopriming, Hydro priming and Control) as factorial considered as sub plots. The results indicated that, the main phonological sunflower stages as head emergence stage (R1), anthesis (R5) and Physiological maturity (R9), significantly affected by planting date, variety and priming. Interaction effect of planting date and variety was significant on head formation. Farokh had faster development stages than azargol variety. Delay in planting time deceased plant height, head height, stem diameter, head diameter and seed yield. Azargol was more succeed in plant height, head height, stem diameter, head diameter and seed yield than farrokh variety. The maximum seed yield gained in 20 Jun (1790 kg/ha), 4 July (1505 kg/ha) and the lowest one belonged to 19 July (774.7 kg/ha). Osmopriming (1441 kg/ha) and hydro priming (1375 kg/ha) treatments had the more seed yield than control (1253 kg/ha).