Abstract: Variety singleness,excessive use of fertilizer,intensive and successive planting,and straw-burning,etc. destroy the balance of soil ecology. As a result,root diseases are intensified. The basic measurement to prevent root disease is to recuperate the soil ecology. The physical and chemical charac teristics of soil,balance of rhizosphere in material and energy,and secretions of different roots in different periods affect the quantities and species of pathogen and the resistance of plant. Application growth promoting rhozobacteria is a new method to modulate soil ecology and promote the health of root. The foregr ound of growth promoting rhozobacteria in framing is promised.