Acanthopanacis Cortex has been used for oriental medicinal purposes in Asian countries especially in Korea and China. In the Korean Pharmacopeia, the cortexes of the dried roots, stems and branches of all species in Eleutherococcus and Eleutherococcus sessiliflorus are known as ‘Ogapi’. Mostly the cortexes of E. gracilistylus roots and E.senticosus roots were used as ‘Ogapi’ in China and Japan, respectively. Therefore, the purpose of this study was to determine and compare the molecular authentication of Korean ‘Ogapi’ by using the ribosomal internal transcribed spacer (ITS) region. The ITS region has the highest possibility of effective and successful identification for the widest variety of molecular authentication. The ITS region was targeted for molecular analysis with Single nucleotide polymorphisms (SNPs) specific for morphologically similar to E. gracilistylus, E. senticosus, E. sessiliflorus from their adulterant, moreover, E. sieboldianus were detected within sequence data. Thus, based on these SNP sites, specific primers were designed and multiplex PCR analysis were conducted for molecular authentication of four plants (E. gracilistylus, E. senticosus, E. sessiliflorus, and E. sieboldianus). The findings of results indicated that ITS region might be established multiplex-PCR analysis systems and hence were proved to be an effective tools for molecular evaluation and comparison of ‘Ogapi’ with other plants.