A liver function protecting or improving agent which comprises a compound represented by the formula (I) ##STR00001## {in the formula (I), R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 may be the same or different, and represent hydrogen, halogen, hydroxy, alkoxy or alkyl; and R.sup.A represents the formula (II) ##STR00002## [in the formula (II), R.sup.10 and R.sup.11 may be the same or different, and represent hydrogen or halogen, or R.sup.10 and R.sup.11 together represent a binding] or the formula (III) ##STR00003## [in the formula (III), R.sup.12 represents hydrogen, halogen, hydroxy, alkoxy, cyano or alkyl, R.sup.13 and R.sup.14 may be the same or different, and represent hydrogen or halogen, or R.sup.13 and R.sup.14 together represent a binding]} or a glycoside thereof or a pharmaceutically acceptable salt thereof.