Objective To improve the policy for control and prevention of hepatitis B on the basis of HBV infection among employees in public food services.Method HBV DNA was examined by PCR and microcell hybridization and fluorescence-based quantitative analyses. Familial clustering of HBV infection was analyzed with the fitness comparison by binomial distribution.Result 1 022 were HBsAg positive among 28 516 employees, the positive rate of HBsAg was 3.58%,among whom 364 (35.64%) employees were transferred from job. However, 234(35.56%) employees were HBV DNA positive in the 658 HBV positive employees who were permitted to retain the job according to law stipulation. Familial clustering rate in HBV infected individuals was 86.49% and the rate of intrafamilial HBV infection was 64.38%.The infection among familial members of HBV DNA positive employees was obviously familial clustering.Conclusion HBV DNA positive employees in accord with law stipulation are still potential spreading sources of HBV.