Strawberry fruit is greatly sensitive to microbial infections and Botrytis cinerea is the most important inhibitory agent of it's postharvest longevity. Sampling was performed from fruit rot and gray mold symptoms during the months of June, July and September of 2012-2013 in several areas of the garden city of Sanandaj, Kamyaran. After surface sterilization, pieces of infected tissue were cultured on PDA medium. Trichoderma species used in the study of soil, roots, stems and leaves of strawberry were isolated and then purified. Four species antagonistic activities T. harzianum, T. arundinaceum, T. atroviride and T. brevicompactum in dualculture test and volatile metabolite, toward biological control Botrytis cinerea in vitro. Result of dual culture test indicated that percentage of growth inhibition varied isolates were T. arundinaceum, T. harzianum, T. atroviride and T. brevicompactum 74, 68, 64 and 59%. Result of volatile metabolite test indicated that percentage of growth inhibition varied isolates were T. arundinaceum, T. harzianum, T. atroviride and T. brevicompactum 47, 43 , 40 and 40%. Result of dual culture showed that T. arundinaceum and result of volatile metabolite showed that T. brevicompactum could important new biological control for Botrytis cinerea of strawberry.
