An experiment was carried out on the mechanism of Lantana camara leaf extract in the management of Meloidogyne incognita on tomato. For this, leaf extract of L. camara (25gm/75ml w/v) were evaluated at 25, 50, 75 and 100 percent concentration through egg hatch inhibition and larval mortality test. Invitro efficacy test showed that maximum egg hatch inhibition and J2 mortality of M. incognita were recorded in the 100 percent concentration of L. camara leaf extract. A pot experiment study recorded maximum plant growth parameters were recorded in the 50 percent concentration whereas; minimum nematode multiplication was recorded in the 100 percent concentration of L. camara leaf extract after 35 and 45 days after inoculation. Further, biochemical analysis of tomato root revealed that maximum activity of the peroxodase, polypheno oxidase and total phenol content was recorded at 35 DAI while the same declined at 45 DAI.