objective:to explore the data management and quality control of the large-scale epidemiological survey study through an example. methods:the quality control was applied in the whole process including quality control system,staff training,field organization,laboratory,data entry and so on,and the data quality was assessed by data checking. results:after the original forms had been verified and the abnormal data had been revised,the error rates of people and the error rates of variable of 3 randomly selected projects were all about 10% and less than 0.5%,respectively. conclusion:there are many factors that can affect data quality in the medical research. it is essential for data quality to develop the reasonable programs of data management and quality control according to the actual situation,although considerable manpower and material resources are required.