Abstract: OBJECTIVE To investigate the distribution of mobile resistant determinants (genetic markers of mobile genetic elements and resistant genes) in a group of drug-resistant Enterobacter cloacae and observe the relationships among the strains. METHODS A total of 20 strains of drug-resistant E. cloacae were isolated from sputum specimens of the patients who were hospitalized from Jan 2015 to Dec 2015. Totally 11 kinds of mobile genetic elements and 20 kinds of beta-lactamase genes, and 16 kinds of resistant genes to aminoglycosides were analyzed by polymerase-chain-reaction (PCR) and sequence analysis, finally, the sample cluster analysis of the results was performed. RESULTS The mobile genetic elements and resistant genes to beta-lactams and aminoglycosides were detected positive in 19 strains of E.cloacae. Totally 5 kinds of mobile genetic elements, including tnp513, tnpU, IS26, IS903, and intⅠ1, 4 kinds of resistant genes to beta-lactams, including blaTEM, blaOXA-1 cluster, blaDHA, and blaACT/MIR cluster, and 6 kinds of resistant genes to aminoglycosides, including aac(3)-Ⅱ, aac(6')-Ⅰb, ant(3″)-Ⅰ, ant(2″)-Ⅰ, aph3'-Ⅵ, and rmtB, were detected positive in 20 strains of drug-resistant E.cloacae. The sample cluster analysis indicated that 18 strains showed aggregation except strain No.2 and 18. Strain No.3-9-10-16, strain No.1-17, strain No.5-14, and strain No.15-19 were clonal spread. CONCLUSION The mobile resistant determinants that are detected in the group of drug-resistant E.cloacae strains are the leading causes of the resistance to beta-lactams and aminoglycosides, furthermore, phenotypes and genotypes are coincided. Four different clones in this group of strains suggest nosocomial infections in the hospital.