Insampaedoksan (IS) is the decoction of medicinal herbs, which was commonly used for anti-inflammatory and anti-pyretic in the Korean traditional medicine (KTM). Several studies on improving efficiency or searching new efficiency by fermenting traditional herbal medicines are recently in progress. The bioconversion has been conducted on IS using various bacteria. Liquiritin, ferulic acid, hesperidin, liquiritigenin, and glycyrrhizin in IS before and after fermented IS were simultaneously analyzed. These compounds were qualitatively analyzed and quantitatively analyzed using the HPLC-DAD system. The identifications of liquiritin, ferulic acid, hesperidin, liquiritigenin and glycyrrhizin were achieved by comparing the HPLC retention time ($R_t$) and the UV absorption of five pure compounds in the IS. As a result, the increased constituents were identified to be liquiritin, liquiritigenin and glycyrrhizin, while the decreased constituent was ferulic acid and the constituent of hesperidin was similar to before and after fermentation. Insampeadock-san fermented by Lactobacillus plantarum KFRI 144 exhibited the most remarkable changes in all of fermentation.