This project detected the protein composition of extracellular vesicles (EV) produced by S. aureus WT JE2 strain and its lgt mutant (lipoprotein deficient mutant). Our recent study found that mutation of lgt in S. aureus USA300 JE2 strain significantly increased EV production in S. aureus and decreased the pore-forming toxin content of vesicles, indicatiung that lipoproteins modulate the EV biogenesis of S. aureus. To gain a better understanding of this process, we detected the protein compositions associated with EVs purified from both WT and lgt mutant EVs by LC-MS/MS. Compared to WT EVs, more cytosoli proteins and less extracellular proteins were identified in lgt mutant EVs. A total of 180 and 198 proteins were identified from WT and lgt mutant EVs, respectively.In addition 27.2% and 33.8% of identified proteins were unique to WT or lgt mutant EVs respectively.