A composition for forming a cured film pattern comprises a combination of: an alkaline developable photocurable and thermosetting composition containing no thermal curing catalyst; and a developing solution comprising an aqueous solution of a basic curing catalyst of a nitrogen-containing heterocyclic compound for promoting a thermosetting reaction so that it has a long pot-life (useful life) after mixing of a main agent and a hardener or has excellent storage stability as a one-package composition. Preferably, the basic curing catalyst is a heterocyclic compound having an amidine structure. A film of the photocurable and thermosetting composition is selectively exposed to an actinic energy ray and then developed with the developing solution to remove an unexposed area of the film. At this time, the basic curing catalyst penetrates into the photocured film to effect doping. As a result, the film becomes excellent in thermosetting properties besides the patterning properties by development.