An X-ray method has been proposed for identifying the coalescence sequences in silicon carbide crystals containing several polytypes in coalescence. The platelet of single crystal silicon carbide is ground layer by layer by ultrasonic technique, and two Laue patterns are taken before and after every layer was ground off. Thus with the aid of these Laue photographs it would be found possible to determine the sequences as well as the ratios of various coalescent polytypes. The experimental results of one crystal were discussed in view of the mechanism of silicon carbide polytypism suggested by Mitchell.