Abstract: Objective To seek for the distribution and clinical characteristics of infectious diarrhea of E coli O 157 ∶H 7 as well as its carrying status in livestock and poultry, and its pollution situation in food Methods The pathogen was isolated and cultured with the specific screening methods of O 157 and the samples of patients, livestock and poultry were isolated, cultured and determined on violent factors with molecular biology, microbiology and biochemistry technologies Results 220 strains of E.coli O157:H7were isolated from 3840 samples and 77 strains of them had violent factors which was divided into 5 typrs.Conchusion The cases showed characteristic distribution on profession and time obviously.Most cases were above 60 years old and the best time of sample collection should be within 5 days after infection.The infectious diarrhea of E.coli O157:H7 presented direct relation with the carrying status of E.coliO157:7 in livestock and poultry.