Fungicides were used successfully for management of different plant diseases worldwide. According to the different human and environmental concerns using of fungicides were mandatory limited. Integration between bio-control agent (Trichoderma) and fungicides was important options. For most effective potential, it is preferred that bio-control agent was tolerant or compatible with the desired used fungicide. In this study, sensitivity of '' different Trichoderma isolates toward different concentrations of chlorothalonil fungicide compared with Fusarium culmorum and acquisition resistance potential of these isolates toward chlorothalonil were measured. Results showed that all tested Trichoderma isolates positively inhibited F. culmorum mycelium growth in vitro. obtained results cleared that both of Trichoderma isolates and F. culmorum were sensitive and no tolerance potential against chlorothalonil was recorded. After using adaptation technique results showed that tolerance potential of all tested Trichoderma isolates toward chlorothalonil was significantly increased. Thus, Acquisition of Trichoderma resistance potential toward chlorothalonil can be used for integrated diseases management.