A pot experiment was investigated to study the effect of arbuscular mycorrhizal (AM), Glomus constrictum (Trappe) on growth response, photosynthetic pigments, gas exchange parameters, antioxidant enzymes and nutrition of pepper plants irrigated with different concentrations of sea water. Four concentrations (tap water, 10%, 20% and 40% of sea water) were used. Salinity stress markedly reduced all studied parameters, except antioxidant enzymes, of pepper plants. Under saline conditions, AM fungi significantly increased growth parameters, photosynthetic pigments, nutrient contents (except Na+), gas exchange rate and antioxidant enzymes of pepper plants when compared to non-mycorrhizal ones. Those improvements were linked to mycorrhizal infection degree in pepper. Generally, growth, nutrition, photosynthetic pigments and antioxidant enzymes of pepper appeared to be highly dependent on the AM in salinized soil compared to non-salinized soil. This study suggested that mycorrhizal colonization could be used to mitigate the detrimental effects of salinity, particularly in soils irrigated with high concentration of sea water.