Abstract: ObjectiveThe effects of chicken manure fermented extract on the tomato growth and control efficiency of root knot nematode were studied to provide reference for scientific use of chicken manure to control root knot nema-tode.MethodEight diluted multiples(5,10,25,50,100,300,500 and 1000 times)of chicken manure fermented ex-tract were used. Clear water was taken as control. Their effects on growth of tomato plants and the control efficiency of root knot nematode were studied by irrigation of the potted tomatoes inoculated with root knot nematodes. The second in-star root knot nematode and root knot nematode eggs were cultured indoor to study the effects of different dilutions of chicken manure fermented extract on lethality of root knot nematode and hatching of its eggs.ResultThe pot experiment results showed that 50,100 and 300 times of chicken manure fermented liquid could promote the growth of tomato plants at early stage. High concentration(diluted 5,10 and 25 times)of chicken manure fermented liquid could enhance the growth of plants at late stage and decrease incidence of root knot nematode with the highest control efficiency of 72.7%. The culture experiment results showed that high concentration(diluted 5,10 and 25 times)of chicken manure fermented diluent could significantly reduce the hatchability of root knot nematode eggs with inhibition rate of 70.0%. Above all,5 and 10 times dilution of chicken manure fermented extract caused obvious lethality to root knot nematodes,with a lethal effect of 100.0% 24 h after treatment.Conclusion5-10 times of chicken manure fermented diluent can promote the growth of the tomato plant,plays an important role in inhibiting the hatching of the eggs and killing the second instar juve-nile and reduce the incidence of root knot nematode. It is a simple and safe method to prevent and control root knot nema-tode disease.