Abstract: To evaluate the effect of bio-organic fertilizers on bio-controlling muskmelon root-knot nematode (RKN) in farming system, a field experiment was carried out in the root-knot nematode severely infected soil. The results were as follows: 1) The incidence of RKN was significantly reduced in the treatments of bio-organic fertilizers with a high control efficiency of 81.14%, whereas high incidence was observed in the chemical fertilizer control; 2) Compared with the chemical fertilizer control, application of the bio-organic fertilizer coupled with strain X5 increased the shoot fresh weight and decreased root fresh weight or amount of root-knots; 3) Application of bio-organic fertilizers effectively reduced the population of the second instar larvae of RKN in soil and egg mass of RKN in roots; 4) The DGGE patterns of nematodes from the soil treated with bio-organic fertilizers and common fertilizers belonged to two corresponding clusters, suggesting that application of bio-organic fertilizers contained the antistatic strains of RKN changed the structure of nematode community in soil. In conclusion, application of bio-organic fertilizers in field conditions could effectively control damages caused by RKN to muskmelon.