In the present study, an experiment was conducted using wheat plants (Triticum aestivum L.) to study the effect of different seaweed treatments on some biochemical changes in the plants. Different five types of seaweed treatments were applied, i.e. Halimeda opuntia, Sargassum aquifolium, Actinotrichia fragilis, and Caulerpa racemosa. The results showed that the wheat plant treated with different seaweeds increased the activity of peroxidase enzymes at the vegetative stage of plant growth. The highest peroxidase activity was observed in the leaf plant treated with Halimeda opuntia. Whereas, Halimeda opuntia catalase activity was increased in leaves after all applied treatments, with a maximum increase in Halimeda opuntia, Saragasum aquifolium, and Actinotrichia fragilis. Further results showed that the level of total carbohydrates and other metabolic activities such as proline and malondialdehyde (MAD) content were raised after all treatments, including the application of seaweeds, i.e. Sargassum aquifolium, Actinotrichia fragilis, and Caulerpa racemosa with wheat plants. However, the highest increase in MAD content was recorded in the leaves treated with Halimeda opuntia. The best algae were Halimeda opuntia and Sargassum aquifolium, followed by Actinotrichia fragilis. The best procedure was the determination of total carbohydrates.