Abstract In order to evaluation of seed (pod) priming and seed size (pod) effects on growth and anti oxidant enzymes activity of sainfoin (onobrychis viciifolia Scop.) seedling in normal and drought condition, this experiment was carried in green house condition in 2010. Treatments (16) included: two masses (Borojen and Ghazvin), two seed sizes (large, >4.5 mm and small, 4.5>…>3.5 mm) and four seed priming ( hydropriming, priming with PEG and CaCl2 and non priming) that were evaluated in a factorial experiment in CRD in drought (use of 80% available water in pot soil) and normal (use of 55% available water in pot soil) conditions. Results showed that dry matter reduced in drought condition for all treatments, but the most weight was obtained from Borojen mass, large size and hydroprimed seedlings in compared with Ghazvin mass, small size and nonpriming in drought condition. Antioxidant enzymes (SOD, POX, APX and CAT) activity in Borojen, large size and hydroprimed seedling treatments were further than Ghazvin mass, small seeds and nonpriming treatments in normal and drought stress. H2O2 in Ghazvin mass, small seeds and nonpriming seedling were higher than other treatments. In sum, results showed that seedling growth, seedling tolerance indexes to drought stress were improved by use of Borojen mass, large seeds and hydroprimed seeds, in drought condition.