We detected the serum testosterone levels in 26 male chronic hepatitis B patients (average age 30.7±6.7 years) with sequential serum samples both at inactive phase (average ALT 42.7±25.4 IU/L, average TBil 14.5±5.9 μmol/L) and hepatitis B flare (average ALT 834.9±491.0 IU/L, average TBil 31.2±28.0 μmol/L). This evidence concerns the gene GPT and hepatitis B virus infection.