A polymer for forming an organic anti-reflective coating layer between an etching layer and a photoresist layer to absorb an exposure light in a photolithography process and a composition comprising the same are disclosed. The polymer for forming an organic anti-reflective coating layer has a repeating unit represented by
wherein, R
1
is hydrogen or methyl group, and R
2
is a substituted or non-substituted alky group of C1 to C5. The composition for forming the organic anti-reflective coating layer includes the polymer having the repeating unit represented by above Formulas; a light absorber; and a solvent.