Enterohemorrhagic Escherichia coli (EHEC) is one type of major contagious and foodborne pathogens.Once infected,the host may exhibit severe symptoms,such as abdominal pain,diarrhea,hemorrhagic colitis and hemolytic uremic syndrome or even death.The type Ⅵ secretion system (T6SS) has been shown to be involved in the bacterial pathogenicity and bacteria-bacteria competition.Here,we identified a typical T6SS gene cluster including 13 conserved T6SS elements in the genome of EHEC O157:H7 by bioinformatics.