${eta}-Glucuronidase-inhibitory$ and hepatoprotective effects of Chungpesagan-tang, which has been used for liver diseases and stroke, on $CCl_4-induced$ hepatotoxicity of rats was investigated. Chungpesagan-tang potently inhibited ${eta}-glucuronidases$. Serum AST, ALT and LDH levels of the $CCl_4$ group orally treated with Chungpesagan-tang (100 mg/kg) were lowered to 47, 28 and 58% of the $CCl_4-treated$ group, respectively. Among the ingredients of Chungpesagan-tang, Puerariae Radix, Scutellariae Radix and Rhei Rhizoma potently inhibited the ${eta}-glucuronidase$ and protected $CCl_4-induced$ liver injury. The hepatoprotective activity of Puerariae Radix was affected by ingredients of Chungpesagan-tang: Scutellariae Radix had the synergistic activity, but Angelicae Tenussimae Radix exhibited the antagonistic activity. These results suggest that the ${eta}-glucuronidase$ inhibitor of herbal medicines may protect $CCl_4-induced$ liver injury and puerarin should be a natural prodrug for the hepatoprotective effect.