OBJECTIVETo follow up the cohort of a certain factory and analyze the death cause of the employees.

METHODSA dynamic cohort was adopted and the study population consisted of all workers stayed at the factory for more than 1 year. The cohort data was mainly from the personnel ministry in the factory,the death data provided by the personnel ministry,the labour union and the hospital. All cause of death of the all employee and the death condition of radiation group and no-radiation group were analyzed and compared.

RESULTSThe mortality of the workers in the factory was significantly lower than national population, the SMR of all cause of death in all employee, radiation group and no-radiation group were 0.41 (95% CI: 0.37-0.45), 0.24, 0.75 respectively; all cancer death in the three group was 0.59, 0.40 and 0.92. But the death order was different in radiation group and no-radiation group,the order of liver cancer was list first in radiation group, which was unlike that of the nation order and the no-radiation order.

CONCLUSIONThere have no excess death in the factory, but the order of liver cancer is precedence.