Under laboratory conditions, three aqueous seed extracts of  Sinapis alba, Ammi visnaga and Lepidium sativum were tested against the root- knot nematode Meloidogyne incognita Exposure of juveniles  and eggs to the tested plant water extract solutions for 72 hr , and 144hr separately reduced the number of active nematodes to J₂ immobility and egg hatching as well. Among tested materials, Lepidium sativum seed extract surpassed other seed extracts treatment in diminishing values of  J₂ immobilityand egg hatching by 94.6 and 5.3% at 72 hr of exposure as well as 63.5 and 1.4% at 144 hr of exposure, respectively. Moreover, treatments of Ammi visnaga and Sinapis alba seed extracts showed considerable percentage of reduction values of  J₂ immobility and egg hatching that averaged 36.4 & 48.5%; and 63.5 & 51.4%; and 60.7 & 69.9% ; and 39.3 & 29.9% at 72 and 144 hr of exposure time, respectively. Combination of plant seed extracts were the most effective in J₂ mobility after 1 and 7 day comparing to control.