Abstract: The antibiotic resistance of primary phase of the bacterium Xenorhabdus nematophila var. pekingensis was assayed with Minimum Inhibitory Concentration (MIC) analysis. The result showed that it is sensitive to chloramphenicol, neomycin, and kanamycin, whereas this strain possesses resistance to streptomycin, ampicillin and penicillin in some degrees, respectively. With approach of conjugation of three parents mating on membrane, plasmid pLA2917 was transferred into strain X. nematophila var. pekingensis. The conjugators were identified and confirmed through PCR amplification and plasmid isolation.