Abstract : Objective To investigate the molecular typing，virutlence ，and drug resistance characteristics of Staphylococcus aureus(SA) in lone and joint infections, providing basis for anti-infection treatment.Methods 'The SA strains isolated from inpatients withbone and joint infections in Beijing Jishuitan Hospital , CapitalMedlical University from January 2014 to December 2021 were collecterd.Muli-locus sequrence typing ( MILST) and Staphylococal A protein ( Spa) typing for all the strains and Staphylococcal cassette chromo-some mec ( SCCma. ) typing of methicillin-resistant Staphyloccus aureus ( MRSA) were performed basert on whole genome sequencing.The vinulence genes and drug resistance genes of the strains were identified by online database. The antimicrobial susceptibility testswere caried by automatic microbiological assay system.Results MRSA acounted for 30.0% of the 100 isolated strains of SA. A totalof 22 ST types and 39 Spa types were identified in the 100 strains of S.aureus , among which ST59 (16.0% ) and ST239 ( 14.0%) werethe dominant ST types，and t437 ( 13.0%) and t030 ( 10.0%） were the dominant Spa types. ST239-SCCmecⅢl-030/1037 clone(46.7%) was the main epidemic elone in MRSA isolates. The bioflm gene ( icaA, icaB , icaC, icaD , icaR) , hemolysin gene ( hlb,hld, hegA, hlgB, hgC') , adhesion gene ( ePfA , cfB, fnbA , finbB, ebp ) , and immume escape gene ( adsA, si , scn) were widespreadin all SA strains， with detection rates ranging from 89.0% to 100.0%. The detection rates of enterotoxin genes seb ( 43.3% ) ， selk(93.8% ） and selq ( 83.3%) inMRSA were significamly higher than those in methicillin-sensitive Staphylococus aureus ( MSSA) ( allP<0.05). In tems of drug-resistance chanacteristics ， the detection rate of the resistance gene blaZ (87.0%) was the highest among allthe S.aureus strains. In the isolated MBSA strains , the detection rate of resistance genes for erm( A ) , tet( M) , aph(3')-Ⅲ, an(6)-la,ant(9)-la，and aae(6')-aph(2") ranged from 43.3% to 50.0%，which were significantly higher than those in MSSA ( all P<0.05 ).The results of the drug-sensitivity test showed that the resistant rates of S. aureus strains to penicillin，erythromycin，and clindamycin were relatively high ( 89.0%，67.0% ， and 51.0% ，respectively). The resistant rates of MRSA to the antimicrobial agents commonlyused in clinical practice were significantly higher than those of MSSA ( all P<0.05). Conclusion The molecular epidemiological char-acteristics of SA strains isolated from bone and joint infections were diversified in our hospital. ST239-SCCme ⅢI-t030/1037 was themost common epidemic clone among the strains. There were significant differences in the resistance genes and drug resistance rates be-tween MRSA and MSSA strains，for which clinical altention should be paid.