Research has shown that the introduction of various antagonists, including Trichoderma fungi into the soil and rhizosphere, could reduce the damage to the disease below the threshold of economic loss. One of the most important mechanisms for biological control is the production of antibiotics and the induction of resistance. In this study, the ability of Trichoderma harzianum Iran2375c fungus to induce Catalase, Guaiacol peroxidase and Ascorbat peroxidase enzymes in cucumber at 0, 24, 48, 96 and 168 days after inoculation of nematode was evaluated. The experiment was a factorial based on completely randomized design with three replications. According to the results of analysis of variance, the activity of Catalase enzyme was significant at 0, 24 and 48 hours at 5% level and 96 and 168 hours at 1% level. The level of activity of the enzyme Guaiacol peroxidase at 0 and 24 hours showed no significant difference, but at 48, 96 and 198 hours at 1% level. And the level of activity of Ascorbic peroxidase at zero time did not show a significant difference but at 24 hours at 5% and at 48, 96 and 168 hours at 1% level. Regarding the mean comparison, treatment of fungi and treatment of fungi and nematode in the Catalase enzyme in 96 hours and treatment of nematode in 48 hours, the amount of enzyme Guaiacol peroxidase in 96 hours and in the Ascorbate peroxidase enzyme, the treatment with fungi and nematode was 96 hours and the fungus treatment reached 48 hours at the highest rate during these five measured time. The results of changes in the activity level of enzymes in different time after inoculation showed that stimulation of induction resistance in cucumber was carried out by T. harzianum Iran2375c against M. incognita nematode.