Provided are a triterpene derivative represented by a general formula (I), a pharmaceutically acceptable salt thereof, and an agent for preventing or treating chronic hepatitis C comprising the triterpene derivative or the salt as an active ingredient:[in the formula (I), R1 represents a carboxyl group, a hydroxymethyl group, -CH2OSO3H, or, and R2 represents -OR3 or -O-(CH2) m-OR4, where R3 represents a benzyl group which may be substituted with a hydroxymethyl group, a dimethylaminomethyl group, a phenylaminomethyl group, a morpholinomethyl group, a carboxyl group, or a formyl group, a C1-6 alkyl group, a C2-6 alkenyl group, a C2-6 alkynyl group, or a hydroxy C1-6 alkyl group, R4 represents a phenyl group which may be substituted with a carboxyl group, and m represents an integer of 1 to 3, with the proviso that a case where R1 is -CH2OH, and R3 is a C1-6 alkyl group, a C2-6 alkenyl group, or a benzyl group is excluded].
