【Background】Radopholus similis is an important quarantine pest that has wide host range and can cause a serious damage. It has become a potential threat to Chinese agricultural production. Because of the high toxicity of chemical nematicides, screening for and identifying potential bio-control microbes antagonist to nematodes is of important significance. 【Method】Soil samples were collected from the banana fields infected by R.similis, and the strains were isolated by the method of gradient dilution. The antagonistic bacterial supernatant and fermentation broth were obtained using shaking flask fermentation technique. Five isolates were screened against R.similis using toxicity tests and pot assay in greenhouse. The antagonistic bacteria were identified by amplification of 16S rDNA gene and sequence analysis. 【Result】Among five isolates, strain HD-86 had the best antagonistic effect with 100% mortality after 24 hours treatment of fermentation supernatant. In greenhouse trial, strain HD-86 showed the highest antagonistic activity against R.similis, compared to other strains and abamectin. HD-86′s performances 42 days and 70 days after fermented inoculation were 77.34% and 90.51% respectively. 【Conclusion and significance】HD-86 has a strong antagonistic to R.similis. Based on 16S rDNA sequence analysis, it was identified as Burkholderia cepacia. The basic basis for the development of nematicide and control of R.similis are provided in this paper.