Rice plants were exposed to increasing concentrations (0, 25, 50, 100 and 200 mM) of NaCl. Fresh weight, dry weight of the treated seedlings decreased. Decreasing of plant growth depended on lowering of available CO2 which was caused by stomatal closure and also on the additive effects of leaf water and osmotic potential, relative leaf water content, and biochemical constituents such as photosynthetic pigments, soluble carbohydrates, and proteins. Increasing concentrations of NaCl resulted in increase and decrease of Na+ and K+ ions respectively. NaCl salinity caused for increasing both peroxide content and lipid peroxidation. Seedlings which recovered for 24 h showed lower peroxide and MDA content.