Ojeok-san has been commonly used to treat low back pain disease. We performed the experiments on simultaneous analysis of 11 compounds and antioxidant effects of Ojeok-san. A HPLC method was established for simultaneous analysis of 11 compounds. The detection wavelengths were set at 230, 254, 280, 320, and 330 nm. The detected 11 compounds from Ojeok-san water extract showed good linearity($r^2{geq}0.9997$). Limit of detection(LOD) and limit of quantification(LOQ) were 0.04-0.87 ${mu}g/mL$ and 0.13-2.63 ${mu}g/mL$, respectively. The antioxidant effects of Ojeok-san water extract were investigated by DPPH and ABTS assays. Ojeok-san water extract significantly increased the DPPH and ABTS radical scavenging effects in a dose-dependent manner. The $RC_{50}$ value of Ojeok-san on DPPH radical was 284.71 ${mu}g/mL$ and that of ABTS radical was 96.16 ${mu}g/mL$.