Objective To explore the protective effect of herbal medicine to tonify qi and strengthen the spleen on liver damage induced by antituberculotic according to the TCM theory "reinforce the earth to reduce the wood".Methods The 100 tuberculosis patients randomized into two groups

50 in each

all took antituberculosis drugs with the liver-protecting medicine

Tiopronin

and the herbal medicines to nourish qi and strengthen the spleen were administered to those in the treatment group.Incidence of liver damage and the changes of liver function including serum alanine aminotransferase（ALT）

aspartate aminotransferase（AST） and total bilirubin（TBiL） were observed for four weeks.Results In the treatment group

the incidence of liver damage was significantly lower than that in the control group（P<0.05）.ALT and AST in both groups were significantly higher（P<0.05 or P<0.01）.The abnormal TBiL cases and their severity of the treatment group were less than those in the control group

but there was no enough cases for statistical comparison.Conclusion The treatment with herbal medicines to tonify qi and strengthen the spleen reduces the incidence of liver damage.