Abstract: The results of experiments showed that synergism between tebuconazole and the bio-control strain of Bacillus subtilis B-916 possessed obvious increasing effects on the mycelia growth of Fusarium spp. and the disease development of faba bean Fusarium wilt. B-916 was marked with rifampicin and used for monitoring B-916 colonization in soil after cooperating. The results showed that tebuconazole can advance B-916 colonization in soil, weaken decline of B-916 quantity, and help showing of B-916 biological control. This was a part of the mechanism of increasing effect of synergism between tebuconazole and the bio-control strain B-916.