The soil was sterilized in autoclave dried properly and used for pot trial. In this soil were two types' normal soil and inoculated soil. The soil in plastic bags were inoculated with mycelial disc of 4 mm size from seven days old actively growing fungal culture and incubated at 28 ± 1°C for 15 days. This culture was then used for further inoculation. The culture was applied @ 30-40 gm kg-1 soil uniformly in each pot. The present investigation was carried out on stem rot (Sclerotium rolfsii) of groundnut with two varieties (GG-20 and GJG-22) and sampling of leaf tissues were done at 2 days after inoculation (DAI), 7 DAI, and 14 DAI from inoculated soil (T2) and sampling time was kept for normal soil (T1) to observe the changes in physiological and biochemical parameters as well as altered enzyme activities due to stem rot infection in groundnut.The changes in various parameters were distinguished clearly in inoculated soil compared to normal soil as well as trend of either increase or decrease observed more prominent with the stage wise progress of stem rot disease in inoculated soil.