Soil salinity has a great impact on decreasing yield potentials of the cultivated crops. The effect of presoaking Zea mays grains in the crude extract of the halotolerant alga Dunaliella bardawil on growth and some metabolic activities of salinized plants was investigated in this study. The Pre-soaking treatment demonstrated a highly significant enhancement in the percentage of seed germination. Moreover, the growth parameters of the pretreated plants were improved at hyposalinity stress conditions comparing with untreated ones. Ahuge augmentation in the soluble carbohydrates, polyols, free amino acids and proline contents was recorded with the pretreated plants at hypersaline stress conditions. GC-MS analysis identified some bioactive molecules in the algal extract such as nicotinamide, xanthine, dihydroxyphenylglycol and linalool that could potentially participate in the alleviation of the salinity stress.