Many reports showed that Trichoderma spp. were potential biocontrol agents against R. solani ( Hadar et al., 1979 and Reithner et al., 2007). The pot experiment was designed to test the in vivo biocontrol abilities of N43 and BIO. The N43 showed biocontrol efficiency on damping-off disease. Furthermore, the control efficiency in BIO treatment was much higher than that in N treatment. These results indicated that the BIO product alleviated or prevented more effectively the damping-off disease in cucumber seedlings compared to the sole application of N43. As reported previously, a combination of antagonistic microbes with organic substrates can more efficiently inhibit disease than single antagonistic microbial strains ( Luo et al., 2010 and Yang et al., 2011).