Abstract: Objective To detect the serum HBV DNA in people infected previously. Methods Past HBV infection people were screened from physical examination persions in Out-patient department. The serum HBV DNA were detected by PCR.Results The positive rate of the serum HBV DNA in past HBV infection people was 3.39%. It was lower than in HBV carriers, χ²= 146.109, P=0.000. Logarithmic Mean of the serum HBV DNA in HBV DNA positive people of the past HBV infection was 3.93±0.90. It was lower than in HBV carriers, F=14.846, P=0.000. Conclusion There are low level HBV reproductions in some past HBV infection people. Its significance needs to study further.

Key words: Hepatitis B virus, Past infection, HBV DNA, Serum HBV markers