This invention relates to a composition for a photo-alignment layer which can exhibit superior thermal stability, alignability, and alignment rate, and can also suppress generation of an afterimage and further improve a voltage holding ratio when applied to a liquid crystal cell, and to a photo-alignment layer and a liquid crystal alignment layer using the same. The composition for a photo-alignment layer includes a cyclic olefin-based photo-alignment polymer and a polyamic acid ester-based photo-alignment additive.