Provided is a composition for forming an organic anti-reflective coating layer used in a negative tone development, which not only enhance an adhesion to a photoresist while having a high refractive index and a high etch rate but also improve a pattern profile of undercut etc. The composition an isocyanurate compound containing at least one moiety which is represented by Formula 2; a polymer represented by Formula 3 and an organic solvent for dissolving the above-mentioned components.