A method of copolymerizing cyclic olefins and polar vinyl olefins, a copolymer produced by the method, and an optical anisotropic film including the copolymer are provided. According to the copolymerization method, a cyclic olefin and a polar vinyl olefin can be effectively copolymerized using a catalyst system composed of a compound containing a group 13 element and a radical initiator. The resulting copolymer is transparent, and has high adhesion, thermal stability, optical anisotropy and strength, and a low dielectric constant. The optical film including the copolymer can be used as a plastic lens, a polarizer protective film, an adhesive film, and a compensation film, and in a LCD display.