The authors provide the description of classification position and morphological characteristics of Trichoderma atroviride, which was collected on peanut-growing soil in the the three provinces Thanh Hoa, Nghe An and Ha Tinh. Evaluation of antagonistic ability of 18 strains of Trichoderma atroviride collected from provinces of Nghe An, Thanh Hoa, Ha Tinh provinces against Aspergillus flavus show that: 8 strains are very high antagonistic (44.44 percent) and 3 strains are high antagonistic (16.67 percent). The cellulose activity of strains of Tri.020 (2)NC representing Trichoderma atroviride is 0.121 umol/ml/min, which is the highest among the strains involved in the evaluation, thus has high potential application in the production of bio-cellulose degradation.