The aim of this study was to determine the concentration of salivary B2M as a marker of viral proliferation in HBS Ag(+), HBV DNA PCR(+) and Hbs Ag(+) and HBV DNA PCR(-) subjects.Beta-2 microglobulin (B2M) is responsible for transmission of viral antigens such as Hepatitis B (HBV) on the surface of liver cells as part of an HLA complex.In this case control study, 25 PCR(+) and 2 PCR(-) patients were included. 5 mL of the saliva sample was obtained from all patients and salivary B2M level was measured using nephelometer. The data was evaluated by the descriptive, chi square and t tests.72% of the PCR(+) patients received medications and in contrast, 85.7% of the patients with PCR(-) did not take any medication (P < 0.001). The average salivary concentration ofBeta-2 microglobulin in the PCR(+) group (5.28 ± 5.45 mg/deciliter) was more than PCR(-) group (1.51±0.77) and this difference was statistically significant (P = 0.003).The salivary B2Mlevel can be used as a marker of viral proliferation in patients with hepatitis B.