Stem of rot disease with Sclerotinia sclerotiorum (Lib.) De Bary, Is one of the major diseases of canola in the world and Iran. The method of chemical struggle has not been effective in the disease And its management is very important in many ways. Effect of 6 Trichoderma isolates Four isolates of (Trichoderma harzianum), A isolate of (Terichoderma viride) and a isolate of (Trichoderma reesei) In addition, two control treatments (positive and negative) and fungicides were investigated on canola stem of rot disease in greenhouse. Rapeseed petals were contaminated with S. sclerotiorum fungi And randomly placed on twenty leaves from each pot Inoculation of suspensions of Trichoderma isolates in one-step process (24 hours after the disease agent) And two-stage (24 hours before and after the disease agent). Lowest incidence and severity of disease In the negative (Without sclerotinia and trichoderma). All fungi in two stages, Effectively were able to reduce the incidence and severity of disease in leaves and stems by the agent Sclerotinia sclerotiorum ARCTr281 (T. harzianum) decreases the incidence and severity of disease in stems and leaves to a rate 33.33 (incidence of disease in leaf), 8% (leaf disease severity), 13.33% (incidence of stem disease) and 4% (severity of disease in stem) were the most effective fungus in greenhouse studies. There was no significant difference with fungus control. Also, the use of Trichoderma isolates in two stages in the greenhouse caused an increase in height, fresh and dry weight of the air and root, number of branches, number of pods, pod length, pod diameter and number of seeds per pod in presence of fungus causing disease. The results of the analysis of the main components showed that the first two components justify a total of 86 percent of the total variation among the data. The relative values of the specific vector coefficients in the first component showed that the weight of the whole grains, pod diameter, branch number, shoot dry weight and root fresh weight were the most important traits in the isolation group. In the second component, the traits of plant height and seed number per pod were important traits. Analysis of variance and comparison of mean of treatments were performed using LSD and nonparametric tests, and a significant difference was observed in the treatments used in greenhouse studies. According to the results of biocontrol studies in greenhouse, ARCTr281 isolate belonging to T. harzianum was the most effective antagonist in control of rapeseed stem of rot disease.