In order to study colonization ability of Bacillus amyloliquefaciens on grape leaves, the strain N24 of Bacillus amyloliquefaciens was induced by rifampicin and streptomycin to obtain double resistant strains. The ob-tained strain could resist 320 μg/mL rifampicin and 150 μg/mL streptomycin stably and its characteristics weresame to wild strain. The experiment results of the double resistant strains colonized on grape leaves showed that af-ter grape leaves were sprayed with 1×10⁴cfu/mL and 1×10⁶cfu/mL of N24, the bacteria amount of double resistantstrains rose steeply from 5th day to 10 th day and reached a peak at 10 th day when the colonization ability and repro-ductive capacity were strongest. Especially when the initial bacterial concentration was 1×10⁶cfu/mL, the amount of N24 reached 1.7×10³cfu/g, then declined after 10 th day. When concentration was 1×10⁸cfu/mL, the amount of dou-ble resistant strains reached peak at 5th day. In conclusion, the most suitable concentration of N24 was 1×10⁶cfu/mL when it was spayed to grape leaves. Adding the synergistic factor was conducive to the colonization of double re-sistant strains on grape leaf surface. Among them, the best was chitosan, followed by threonine. When potassium hy-drogen phosphate was added, there was no significant difference with control.