In order to develop the high refractory composite materials consisting of mullite and carborundum, Hadong kaolin and coal coke were selected as the starting materials. Silicone carbide crystals formed during the high-temperature reaction between kaolin and coke were detected by X-ray diffraction method and identified by electron diffraction. The temperature at which the amorphous silicone carbide begins to crystallize could be assumed to be about 155$0^{circ}C$, which is the lower temperature claimed by others.