A composition for forming a resist underlayer film which make possible to form a desired high-adhesion resist pattern. A resist underlayer film-forming composition for lithography containing a polymer having the following structure Formula (1) or (2) at a terminal of a polymer chain, crosslinker, compound promoting crosslinking reaction, and organic solvent. (wherein R1 is a C1-6 alkyl group optionally having a substituent, phenyl group, pyridyl group, halogeno group, or hydroxy group, R2 is a hydrogen atom, a C1-6 alkyl group, hydroxy group, halogeno group, or ester group of —C(═O)O—X wherein X is a C1-6 alkyl group optionally having a substituent, R3 is a hydrogen atom, a C1-6 alkyl group, hydroxy group, or halogeno group, R4 is a direct bond or divalent C1-8 organic group, R5 is a divalent C1-8 organic group, A is an aromatic ring or heteroaromatic ring, t is 0 or 1, and u is 1 or 2.)