Provided is an optical film, which is capable of fully keeping close cooperation between the active energy radial solidifying layer and the acylation cellulose membrane even exposed to sunlight for a long while. Even as polaroid protective film assembled to Polaroid and used for a long time at a high temperature, the optical film can still keep excellent polarization performance. Moreover, the thickness of the optical film is reduced. In addition, the invention also provides a polaroid and a liquid crystal display apparatus employing the optical film. The optical film of the invention is provided with an acylation cellulose membrane and an active energy radial solidifying layer. The acylation cellulose membrane comprises at least one plasticizer selected from the group consisting of a carbohydrate ramification, polyol ester, and contracting polyester. Moreover, the active energy radial solidifying layer comprises hindered amine compound.