The present invention relates to a plastic reflector having high reflective properties and the method of preparing the same. The reflector is obtained by disposing a reflective film in which a light-reflective metal is coated by a vacuum coating method on one or all sides of a molded body made of polymeric materials or the derivative thereof and further by disposing a light-transmissible coated film in which an inorganic substance selected from metallic oxides and oxides of amphoteric elements or a derivative thereof is vacuum coated on the reflective film.