Background: Hepatitis B virus (HBV) infections are one of the world's health problems that annually kill about 500,000 to 1,200,000 people. Investigation of HBV DNA in the person infected with HBV is a definitive indicator of activation and replication of HBV.Objectives: The aim of this study is to investigate the DNA of HBV in HBsAg positive patients and to study the risk factors for virus activation. Methods: This study was conducted on 106 HBsAg positive patients from January 2020 to July 2020 in Kabul. After informed consent, 3 to 5 milliliters of blood was collected for the HBV-DNA testing using the Real-time PCR method.Result: Out of 106 HbsAg positive patients, 74 (69.8%) were males and 32 (30.2%) females. The patients were aged between 11 and 65 years. Hepatitis B virus DNA was positive in 58 (54.7%) of the samples, 41 (70.7%) were male and 17 (29.3%) were female. The viral DNA load was in the range of 9.85 x 102 to 9.3 x 108 copies/ ml. Most of the patients were aged between 20 and 30 years. Conclusion: From 106 HbsAg positive patients, 23(39.7%) were in the age group of 20 – 30 years, and males were more infected than females. The majority of the patients were married and had an informal job with education below grade 12. No specific differences were found in the availability of HBV DNA between patients who received hepatitis B treatment before and those who did not.