Abstract: Objective To identify the cause, transmission route and affected areas of an outbreak of typhoid fever occurred in Cixi, Zhejiang province,during January-June,2014. Methods An epidemiological case survey and a 1:1 case-control study involving 76 cases were conducted respectively. Results A total of 91 cases of typhoid fever were reported with the incidence of 6.20/100 000. Most cases were local adults (90%). The incidence curve showed double peaks. The cases were mainly distributed in urban area with the spread to surrounding area. The case control study indicated that the disease might be caused by eating raw blood clam (OR=5.00,95%CI: 1.57-21.62), but the hygiene investigation showed that this possibility was low. The stratification analysis showed that using contaminated well-water to wash sea foods was the main risk factor (OR=22.89,95%CI: 2.73-503.40). Conclusion Using contaminated well-water was possible risk factor for this outbreak. It is suggested not to use well-water in the all the markets. In addition, the supervision of water quality should be strengthened and the promotion of rural water project should be continued.