Abstract: Using Trichoderma spp. to control plant soil-borne diseases is a promising field in biological control. In order to investigate the effect of T. asperellum T-6 on tobacco growth and resistance to soil-borne fungi, spore suspensions of T. asperellum T-6 were inoculated into soil, and then pot experiments were conducted in greenhouse. The results showed that hyphal growth of Phytophthora parasitica and Thielaviopsis basicola was inhibited by T. asperellum T-6, and the inhibited rates were 49.62% and 59.23%, respectively. Control efficiency of T. asperellum T-6 on black shank and black root rot reached 74.45% and 75.14%. After T. asperellum T-6 pretreatment, the content of chlorophyll and carotenoids and the activities of three resistance-related enzymes in tobacco leaves were increased, and the growth of tobacco treated with T. asperellum T-6 were better than control. Taken together, the results from this study indicated that T. asperellum T-6 could control tobacco black shank and black root rot effectively, and promote tobacco growth.