Abstract: When we add trace elements and organic mass into bio-controlling strains suspending liquid, its prevention and cure effects increase on the soybean root rot. Adding trace elements can improve the plant nutritional condition and intensify its anti-virotic capacity, the effects are superior to chitin. Adding methyl-cellulose, the prevention and cure effects increase by increasing carbon-nitrogen ratio and prevented the germination of pathogenic spores. Adding chitin and methyl-cellulose, un-suitable carbon-nitrogen ratio can affect the prevention and cure effects of the bio-controlling strains.