An aromatic ring-containing compound for a resist underlayer and a resist underlayer composition, the aromatic ring-containing compound being represented by the following Chemical Formula 1: wherein, in Chemical Formula 1, R1 to R6 are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C5 to C20 aromatic ring group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 cycloalkenyl group, a substituted or unsubstituted C2 to C20 heteroaryl group, or a substituted or unsubstituted C2 to C20 heterocycloalkyl group, X1 to X6 are each independently hydrogen, a hydroxy group (—OH), a substituted or unsubstituted alkyl amine group, a substituted or unsubstituted alkoxy group, or an amino group (—NH2), n1 to n6 are each independently 0 or 1, and 1≦n1+n2+n3+n4+n5+n6≦6.