The fungus of Trichoderma viride Pers. as an antagonist soilborne fungal desease. It can utilise for seed and soil treatment for suppression of various diseases caused by fungal pathogens. Trichoderma viride can grow well on PGA medium with pH from 5 - 7, and 25 - 35° C tempriture condition. The effective in vitro tests of Trichoderma viride for antagonism against Sclerotium roltsii Saccardo and Aspergillus niger van Tieghem ranged from 51.76 percent to 84.70 percent. Trichoderma viride best grow on rice husk enviroment, then bagasse or coffea husk enviroment. The treatment Trichoderma viride to groundnut seed before use in pot condition, effect antagonism against ranged from 92.90 - 93.18 percent. The using Trichoderma viride showed that it is promising candidate for the biocontrol of fungus disease soil born.