In this study, an effective high performance liquid chromatography-diode array detector (HPLC-DAD) method was established for simultaneous determination of six marker compounds, ephedrine hydrochloride, 6-gingerol, glycyrrhizin, hesperidin, imperatorin and ferulic acid, in a Korean traditional prescription, Oyaksungisan, which is used for hemiplegia, arthralgia and paralysis. The six marker compounds of Oyaksungisan were separated on a LUNA C18 column (S-5 μm, 4.6 mm I.D. × 250 mm) at a column temperature of 35°C. The gradient elution was composed of water with 0.1% trifluoroacetic acid and methanol. The detection UV wavelengths were set at 207, 250, 280 and 320 nm. Calibration curves for the six compounds showed good linear regressions (R (2) > 0.9999). The limits of detection and limits of quantification were within the ranges 0.003-0.01 and 0.01-0.04 μg/ml, respectively. The relative standard deviation (RSD) values of intra- and inter-day testing were within the ranges 0.10-1.82 and 0.04-1.59%, respectively. The results of the recovery test were 95.05-104.27% with a RSD value of 0.11-1.85%. In conclusion, the simultaneous determination method developed was useful in the quality evaluation of Oyaksungisan.