Abstract: objective The present inveshgafion was designed t0 find out the epidemiological fea-tures and epidemic factors of paratyphoid A outbreak epidemic occurring at the end of 2004 in avillage of the outskirts in Hangzhou City，provide the basic information for enteric infectious dis-eases，such as typhoid，prevention and control．Methods On-site inspection，sample collection and Epidemiological investigation of cases were adopted．Resnlts A total of 186 cases were af-fected in the outbreak with an incidence rate of 12.48％，diagnosis made in 98 cases through lab tests and in 88 ones clinically It was showed by the monitoring of samples of water resources and pipe water that the drinking water was severely contaminated Conclusion It is seen that drinking water contamination is a major factor contributing to the ombreak of paratyphoid A So the im-provement of water supply and toilet facilities should be vigorously strengthened for the avoidance of such occunenccs