The effects of salicylic acid (SA) on germination, seedling and adult plant of rice (Oryza sativa L.) were investigated. Four cultivars, traditional (Taroom mahalli and Taroom deilamani) and improved (Shafagh and Onda) were studied. For germination, seeds were sterilized and then placed on Petri dish at 30oC at different concentrations(0, 3, 6 and 9 mmolL-1) for 7 days and growth factors of seedling were measured after 14 days. Seedling (10 days) planted in hydroponic medium with nutrient solution amended with 0, 15, 30 and 45 mg kg-1 SA. After 30 days, growth factors were determined.á-amylase and peroxidase activities were assayed by Bernfeld and Maehly methods, respectively. Our results revealed that in all cultivars germination percentage, rate and á-amylase activity have decreased with increasing concentration of SA. In all cultivars, seedling growth factors such as shoot length, fresh weight and dry weight as well as root have reduced with increasing of SA. In adult plant, shoot and root length reduced with increasing concentration of SA in all cultivars but in none of cultivars fresh and dry weight in root and shoot did show significant difference. chlorophyll content had reduced with increasing concentrations of SA in Shafagh and Onda( improved cultivars).Peroxidase activity in Shafagh and Onda (improved cultivars) increased.

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