A pattern-forming method includes forming a resist underlayer film on a substrate using a resist underlayer film-forming composition. The resist underlayer film-forming composition includes a base component, and a crosslinking agent. The crosslinking agent has a partial structure represented by a following general formula (i). X represents an oxygen atom, a sulfur atom, or —NR—. R represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, or an aryl group having 6 to 30 carbon atoms. n1 is an integer from 1 to 6. R1 represents a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, or an aryl group having 6 to 30 carbon atoms.