These studies were attempted to investigate the therapeutic effect of Aster yomena extract on the liver damage induced by carbon tetrachloride (CCl₄) in rats. Male rats (SD) were treated with acute concentration of CCl₄, which was 1 ㎖/㎏ of CCl₄ via s.c injection for 3 days or 0.25, 0.5 ㎖/㎏ of CCl₄ via i.p injection. MeOH Ex. administration to rats (500 ㎎/㎏, p.o, twice a day) did not significantly decrease the increment in serum transaminase activities, but is`s frations (Frs), EtOAc and BuOH Fr., administration to rats (300 ㎎/㎏, p.o) significantly (p<0.05) decreased the enzyme activities (GOP, GPT) and liver enlargment. From histopathological observations, we could find that it`s administration prevented the development of fatty liver, necrosis and cytoplasmic vacuolations induced by CCl₄, and it gave a good agreement with the serological data. Futhermore, in doseresponse test, EtOAc Fr. administration at a dose of 400 ㎎/㎏ exhibited the most significant (p<0.01) activity, but it is net dose-dependent. This hepatoprotective effect was observed after 2 days from the last injection of CCl₄. From these results, we could suggest that Aster yomena contains a certain constituent in EtOAc or/and BuOH Fr. related a hepatoprotective activity for CCl₄-induced hepatotoxicity and we are investigating it`s active compound.