Emodin and chrysophanol in Zhiganshu capsule were detected by RP-HPLC. The separation of samples was performed on a column of Shima-pack C18 column (150 mm×4.6 mm, 5 μm). The mobile phase consisted of methanol-glacial acetic acid (85:15), with a flow rate of 1.0 mL/min. The detection wavelength was set at 450 nm. The linear range of emodin was 0.124-0.744 μg, (r=0.9998), the average recovery rate was 97.10%, RSD=1.60%. The linear range of chrysophanol was 0.128-0.768 μg, (r=0.9999), the average recovery rate was 96.84%, RSD=1.14%. The method is simple, accurate and can be used as the preparation method for the determination