Laboratory experiments were conducted to study the effect of the aqueou extract of the vegetative parts of the Euphorbia paralias at different concentrations (2%,4%,8%) in seed germination and seeding growth of the Lepidium sativum, Lactuca sativa and Portulaca oleracea. The results indicated increase in germination ratio of Portulaca oleracea. up to 7%. while the effect of the extract was not evident in the germination of the seeds of Lepidium sativum, and decreased the germination ratio of Lactuca sativa seeds by 35.9% at the concentration of 8%.In contrast, the extracts stimulated the length of the stalks of Portulaca oleracea , Lepidium sativum and Lactuca sativa plants at all used concentrations used. The highest rate of stimulated stalks legnth of Lepidium sativum at 2% was 58.2%. inhibitory effect of water extract observed for root length of Portulaca oleracea and Lactuca sativa plants at 2% , and stimulation effect pour Lepidium sativum, The effect became evident at the concentrations of 4% and 8% for the three plants. The most sensitive and affected plants was Portulaca oleracea, where the length of the root decreased by 53.38% at the concentration of 4% and by 72% at the concentration of 8% ,while the length of the root Lepidium sativum and Lactuca sativa decreased by 25.82% and 34.95% was decreased for 4% and 8%respectively. The results suggested that this weed may affect seedling growth, due to inhibitory or stimulatory effect of Allelochemicals , which present in water extract of this weed . and may used as potential Bioherbicide after further experiments.