The aim of this study was to study the quantitative analysis of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with Paecilomyces japonica, Ganoderma lucidum, honey or Nuruk. The amounts of dry on loss were measured and the quantitative analysis of glycyrrhizic acid was performed by high performance liquid chromatographic (HPLC). HPLC method was performed on C18 column ($250;mm;{ imes};4.6;mm$, $5;{mu}m$, RS tech) using gradient solvent mixtures of water-acetonitrile with photodiode array detector (254 nm). The flow rate was $1.0;m{ell}/min$. Retention time of glycyrrhizic acid was about 23.96 min and linearity of calibration was $R^2$=0.9998. Contents of glycyrrhizic acid in Glycyrrhizae Radix extract (control) was $5.048;{pm};0.14$; Contents of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with Paecilomyces japonica (SDT) was $1.975;{pm};0.07$; Contents of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with Ganoderma lucidum (SYT) was $2.676 ;{pm};0.07$; Contents of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with honey (SST) was $5.191;{pm};0.06$; Contents of glycyrrhizic acid in Glycyrrhizae Radix extract fermented with Nuruk (SNT) was $5.305;{pm};0.34$, respectively. Contents of glycyrrhizic acid in SDT and SYT were decreased but that in SST and SNT was increased when compared to control.