Abstract: To investigate the effect of rubella virus (RV) Co-infection on fluctuation of liver function and HBV replication in patients with chronic viral hepatitis. Sera from 32 cases with chronic viral hepatitis were defected for RV IgM antibodies, HCV antibodies, sera sign of HBV and biochemical perameters. Control sera taken from twenty normal persons were tested for RV IgM antibodies. Frequency of RV IgM antibodies in patients with chronic hepatitis B was 45.4%, in patients with chronic hepatitis C were 47.5%. Levels of total γ-GT and ALT in RV positive cases were higher than those in RV sera negative ones. Their convalescences of liver function become longer, accompanying with the aggravation of fever, vomit and hepatomegaly. The results suggested that the patient's liver dysfunction was deteriorated by RV Co-infection.