Abstract: A total of 132 soil samples were collected from Xinjiang, Fujian and Zhejiang provinces to study the effects of different cropping system and cultivation pattern on the amount of bacterial populations and the distribution of anti-fusarium wilt bacteria in melon soils. The results of plate counting showed that the amount of culturable bacteria was 15.2 times higher in melon soils than in uncultivated soil, 1.0 times higher in rhizosphere than in non-rhizosphere, 2.5 times higher in the soil with rotation than in that with monoculture, and 0.5 times higher in the soil with non-graft than in that with graft. The Biolog determination of anti-fusarium wilt bacteria in melon soils showed that the soil with water-drought rotation or graft had more antagonistic bacteria, and more than 80% of them were classified as fluorescent Pseudomonas spp.