The main objective of this study was to characterize the molecular characterization of ciprofloxacin-resistant salmonella and the relationship between virulence and resistance of these strains isolated form sick animals.Thirteen non-duplicate ciprofloxacin-resistant salmonella were examined by PCR for plasmid-mediated ESBL and quinolone resistance(PMQR) genes.The QRDR of topoisomerase genes was also sequenced.The detection of efflux pump activities to antibiotic resistance was determined by the addition of carbonyl-cyanidem chlorophenylhydrazone(CCCP) and the organic solvent tolerance experiment.The invasion ability was detected through the adhension and invasion assay to Hela cells,when compared the ciprofloxacin-resistant strains with the susceptible isolates.And this sturdy also detected the expression of the virulence genes using the real-time quantitative PCR(RT-PCR),the purpose is to further determined the deference of the invasion ability between the ciprofloxacin-resistant strains and the susceptible isolates.The qnr,aac(6′)-Ib-cr and oqxA genes were detected in 13 of the isolates and were frequently co-prevalent.7 isolates demonstrated reducing susceptible or low resistant for ciprofloxacin with MIC from 0.125 to 4(g/ml.These isolates had either single mutation in gyrA or no mutation in any target genes as well the active efflux.Five isolates except one presented double mutations in both gyrA and parC and the active efflux conferring high resistance-level to ciprofloxacin (MIC,32-128(g/ml).