This invention relates to a method for making a graphite sheet or block which comprises hot pressing at least two films of a polymer selected from a polyoxadiazole, an aromatic polyamide and an aromatic polyimide at a pressure not lower than 0.4 MPa (4 kg/cm²) at temperatures not lower than 2200°C. Alternatively, the at least two films may be thermally treated at temperatures of not lower than 2200°C and subsequently hot pressed at a pressure of not lower than 0.4 MPa (4 kg/cm²) at a temperature of not lower than 2000°C when the at least two films are made of the polyoxidiazole or aromatic polyamide or at a temperature of not lower than 1600°C when the at least two films are made of the aromatic polyimide.