Drought stress is one of the most limiting factors on crop production. Priming is one of techniques for improving seed germination, increasing stress tolerance and seedling establishment under low moisture conditions. A laboratory experiment used to evaluate the effects of different priming agents and duration on seed sesame. A factorial experiment base on completely randomized design (CRD) with three replications were conducted in the seed science laboratory of College of Agriculture Isfahan University in 2009. In this experiment, nine seed treatments ( consist control, -2, -5 -10 and -15 bar poly ethylene glycol, 0/3, 1 and 2 molar NaCl and hydropriming with distilled water) were as first factor and five treatment periods ( consist 4, 12, 16, 24 and 48 hour) were as second factor. Germination percentage, germination rate, radicle and shoot length and dry weight were measured. Osmotic potential treatments with PEG solution in low level and hydropriming with different duration enhanced percentage and rate of germination, radicle and shoot lengths and dry weight in comparison with control and halopriming with high concentration of NaCl. Osmopriming for 24 hour was the best among the other primings, therefore it wa selected for field experiment. A field experiment was conducted at the Agricultural Research Farm of Isfahan University of Technology in 2009 to evaluate the effects of select seed treatment and different irrigation regimes on sesame. The main-plot consisted of four irrigation regimes (75, 100, 120 and 150 mm cumulative evaporation from class A pan) and sub-plot consisted of two seed treatment ( osmopriming and control). The duration from planting to seedling, 50 % flowering, pod formation and physiological ripening growth stage were significantly shorter in osmopriming than in control. The level of soil moisture did not effect duration of any growth stage. Plant height, leaf area index, number pod per plant, number seed per pod, grain weight, plan dry matter and harvest index were higher in osmopriming compared to control. Plant height, leaf area index, number pod per plant, number seed per pod, plan dry matter and harvest index were reduced as the level of soil moisture was decreased. Regardless of the level of soil moisture, grain yield was 12.1 % by osmopriming. The grain yield was more at higher level of soil moisture. The oil percentage and oil yield were higher in osmopriming compared to control. Oil percentage decreased as the level of soil moisture reduced while; the protein percentage increased. The highest oil and protein yield were obtained from osmopriming with irrigation level of 75 mm and the lowest amount of oil yield and the lowest amount of protein yield were achieved from control in irrigation level at 150 mm evaporation . The results showed that osmopriming enhanced seed germination and seedling growth under lab condition and increased emergence and crop yield and