The root-knot nematodes (Meloidogyne spp.) are an important group of plant pathogens that have a wide range of hosts that every year, they are one of major cause of damaging to agricultural crops. Several methods are used to combat these nematodes (Meloidogyne spp.), But the use of medicinal plants is one of the safe methods for inhibiting their activity. Essential oils are generally the remains of the main processes of plant metabolism, especially in tension situations. Plant essential oils, especially methotropenes, have a great effect on killing nematodes and the use of them as the purpose to kill nematodes does not have much cost. In this study, the inhibitory effect of interaction between essential oils of Teucrium polium and Ferula assa-foetida L. on root-knot nematodes in tomato chips was evaluated. In vitro conditions at 28 ± 3 ° C, microtitudes containing 100 μl of concentrations of 1000, 2000,3000 and 4000 ppm of essential oils and 900 μl of suspension of nematodes containing 150-200 larvae of the age of two nematodes of M. javanica were added. In order to investigate the effect of essential oils on hatching, 900 μl of suspension of nematodes containing 500 eggs were added to microtubes containing 100 μl of concentrations of 1000, 2000, 3000 and 4000 ppm essential oils, under the same conditions of the above mentioned. Each treatment was repeated three times for both the larval stage and the egg. Control treatments also contained sterile distilled water. The results showed that by increasing in concentration of essential oil, the larval mortality rate increased and the amount of hatching egg decreased. In the highest treatment, the essential oil concentration was 4000, 70 and 64% (as compared to control) for larvae and eggs, respectively. The probit analysis showed that the interaction of the essential oils mentioned in LC50 = 311ppm for egg nematode and LC50 = 773ppm for larvae of M. javanica had the highest toxicity. The results of this study showed that interaction of essential oils of Teucrium polium and Ferula assa-foetida L. has potential application in biologic control programs of root-knot nematodes (Meloidogyne spp.).