Rice root-knot nematode, Meloidogyne graminicola is an important endo-parasite of various cultivated crops. Life cycle and pathogenicity of this nematode was studied under screen house condition. It completed its life cycle (J2-J2) in 23 days at mean maximum and minimum temperature 34.12 °C and 25.57 °C, respectively. Study show that plant growth parameters viz. root length, shoot length; fresh and dry plant weight was adversely affected with increasing nematode inoculum level. Low nematode inoculum level (500 J2/kg soil) was found as pathogenic level.