〔Abstract〕 To investigate the hemolytic phenotypes of Staphylococcus aureus clinical isolates . Methods The hemolytic phenotypes of 105 Staphylococcus aureus isolates were analyzed and summarized using the three-point inoculation method . Real-time fluorescence quantitative PCR was used to measure the mRNA expression levels of four hemolysin genes (hla , hlb , hlc , and hld) ; The VITEK 2 GP639 antimicrobial susceptibility card was used to detect resistance to commonly used antibiotics; DNA gel electrophoresis was performed to determine the prevalence of the mecA , sea , tst , and pvl genes; The microtiter plate crystal violet staining method was used to assess biofilm formation ability; The CCK-8 assay was used to evaluate cytotoxicity against macrophages . Results Seven hemo- lytic phenotypes were identified among the Staphylococcus aureus clinical isolates . Differences were found among Staphylococcus aureus clinical isolates with different hemolytic phenotypes in terms of mRNA expression levels of he- molysin genes , antibiotic resistance , virulence gene prevalence , biofilm formation ability , and cytotoxicity to mouse macrophages ( P < 0. 05 ) . Conclusion Staphylococcus aureus clinical isolates exhibit diverse hemolytic pheno- types , which should be a focus across multiple dimensions , including microbiological testing , clinical treatment , and nosocomial infection prevention and control .