Highly crystallized graphite film as a novel host material for graphite intercalation compound was prepared from a high-modulus-polyimide-film by carbonizing and then graphitizing it at high temperatures. Characterization of the graphite films obtained was made by measurements of interlayer spacing d(002), mosaic spread, residual resistivity ratio and Shubnikov-de-Haas oscillation in Hall resistivity, and electron channeling micrography in a scanning electron microscope. All results of characterization show the high crystallinity of the present graphite films. Intercalation of FeCl3 into the graphite film was carried out in a chloroform solution at room temperature. Enhancement of electrical conductivity was observed.