Problem of HBV and HCV coinfection is controversial. HCV superinfection seems to be the co-factor of HBV infection, so as factor inhibiting HBV replication. According to some authors in HBV, HCV co-infection more advanced morphological liver changes and progression to hepatocellular carcinoma were observed. It concerns so patients with active as an "occult" hepatitis B. In this work the results of our own investigations were presented in which beneficial influence of HCV superinfection on chronic B hepatitis in children was revealed. Our study confirmed opinions of both viruses interference.