The present invention relates to a liquid crystal alignment layer of a liquid crystal display that can minimize drop blemishes of liquid crystal in the ODF process. The present invention provides a composition of a liquid crystal alignment layer comprising a diamine compound represented by Formula 1 below, an acid anhydride, and a solvent, in which the diamine compound represented by Formula 1 has a concentration of 15-40 mol %: where R is a C10-C30 saturated or unsaturated alkyl, allyl, or aromatic hydrocarbon that is substituted by a heteroatom or is unsubstituted. The invention also provides a liquid crystal alignment layer and a liquid crystal display that comprises the liquid crystal alignment layer.