To understand the distribution of Escherichia coli O157 (E. coli O157) in human beings, livestock and fowls in Fujian Province, and biological features of the isolated strains.Fecal specimens from diarrheal patients, livestock and fowls and meat specimens in Putian and Fuzhou were collected for detection of E. coli O157 during 1997 - 1998.A total of 2,725 specimens were detected, and 76 strains of E. coli O157 were isolated from pigs, pigeons, cattle, chickens, ducks, et al., as well as from the diarrheal patients. These strains could be classified into three types according to their serological tests, including 33 strains of O157: H7, 21 strains of O157: NM, and 22 strains of O157: H?. Detecting rate of E. coli O157 from pigs was the highest. The isolated strains could cause diarrhea in human and obvious pathological changes in the intestines of mice, but could not produce cytotoxin Vero, or heat-stable or heat-liable enterotoxin LT or ST.There were three types of E. coli O157 in Fujian. But, pathogenic factors of O157: H7 and O157: NM were different from those reported abroad. It suggested that there possibly existed some new pathogenic factors.