The present work was conducted to evaluate the effect of aqueous extract of Alhagi maurorum at different rates (1, 5, 10, 15%, w/v) on the growth as well as some physiological parameters of pea (Pisum sativum L.). The pot experiment revealed that Alhagi maurorum aqueous extract reduced all growth parameters of pea plant along with photosynthesis pigments, insoluble sugars, total carbohydrate, total protein and total phenolics. On the other hand, soluble sugars, soluble protein, proline, flavonoids and antioxidant enzymes increased upon treatment with aqueous solution of Alhagi maurorum. The adverse effect of the extract on the growth of treated pea plants especially hydroquinone and sinapyl alcohol that were found in relatively high concentration in the extract were identified and quantified by the GC–MS of the methanolic extract of Alhagi maurorum.