Abstract: To explore the effect of different concentrations of symbiotic bacteria of entomopathogenic nematodes (EPNs) on egg hatching of southern root-knot nematodes (Meloidogyne incognita), egg hatching rate was investigated at different interval time points by mixing with symbiotic bacteria in the Petri dishes in the laboratory. The results showed that the lowest egg hatching rate in 10×dilution of symbiotic bacteria of Hb-NJ (EPN) at 6 d was 8.6% while it was 29.1% compared with the control medium TSY. The strongest inhibition rate of 10x dilution of symbiotic bacteria of Hb-NJ on M. incognita egg hatching was at 6 d, with 70.6% of relative inhibition rate. The egg hatching rates in 10×dilution of symbiotic bacteria of Hb-IGA, Sc-All and Sf-IGA at 6d were 24%, 22.6% and 25.2%, and their inhibition rates were 17.2%, 22.3% and 13.4%, respectively. At 8 d, the inhibition rates of symbiotic bacteria of Hb-NJ, Hb-IGA and Sc-All were 67.1%, 39.3% and 41.7%, respectively, and were significantly greater than that of Sf-IGA (11.1%). At 10 d, the egg hatching rates and the inhibition rates by the 10x dilution of the four tested symbiotic bacteria had no significant difference. No obvious inhibition effect on M. incognita egg hatching was examined when using 20x and 50x dilutions of symbiotic bacteria at all tested days. Based on the results, the symbiotic bacteria of Hb-NJ might be a promising bio-agent to control root-knot nematodes through inhibiting M. incognita egg hatching and consequently result in decreased M. incognita infection.