To explore the effect of Hejie decoction (HJD) (mediation decoction) on T cellular immune state of chronic hepatitis B patients. Sixty-five patients with chronic hepatitis B were randomly divided into 2 groups. Forty patients in the treatment group were treated by HJD, and 25 patients in the control group were treated by routine Western medicine. The TCRVbeta7 gene expression, T lymphocyte subsets (CD3+, CD4+, CD8+, CD4+/CD8+) levels were observed before and after treatment. The level of CD4+ cells was lower whereas the level of CD8+ cells was higher in patients than in the normal group. There was no significant difference between the levels of CD3+ cells in patients and normal persons. After 6 months of treatment, ALT, AST, TB levels of the 2 groups were obviously decreased, and the level of CD4+ cells was increased whereas the level of CD8+ cells was decreased in the treatment group. However, the level of CD4+ cells and CD8+ cells had no significant difference in the control group. TCRVbeta7 expressions were detected in 6 patients of the treatment group, whose HBV-DNA and HBeAg turned negative and ALT became normal. HBeAg in another 3 patients turned negative while HBV-DNA did not, and TCRVbeta7 expressions were not detectable. TCRVbeta7 expression could not be detected in the control group, HBV-DNA of the control group did not turn negative. HBeAg in 1 patient turned negative while HBV-DNA did not, and TCRVbeta7 expressions were not detectable. The total effective rate was not significantly different between the 2 groups and the markedly effective rate was significantly different (P<0.01). HJD is effective for treating chronic hepatitis B, and its effect seems to relate with the improvement of the TCRVbeta7 expression of chronic hepatitis B patients, thus activating T cells and eliminating HBV. T cellular immune function plays an important role in HBV infection and virus elimination.