The present invention relates to a genotyping method, and more particularly to an ID sequence, which is assigned to each genotype, and a multiplex genotyping method which uses the ID sequence. When pyrosequencing is performed using the ID sequence, a unique and simple pyrogram can be obtained for each genotype. Thus, the use of the ID sequence makes it possible to genotype viral genes, disease genes, bacterial genes and identification genes in a simple and efficient manner. In addition, a genotyping primer of the invention can be used in various genotyping methods which are performed using dispensation orders and sequencing methods.