Objective To establish a RP-HPLC method for the determination of 3-amide-indole derivative and its related substances. Methods Diamonsil C18(250 mmí4. 6 mm,5 μm) column was adopted. The mobile phase consisted of a mixture of methanol-acetonitrile-water(431245) at the flow rate of 1. 0 mL·min-1 . The wavelength for ultraviolet detection was 224 nm. The injection volume was 20 μL and the column temperature was room temperature. Results 3-amide-indole derivative and related substances could be well separated. The linearity of the 3-amide-indole derivative curve was well correlated (r=0. 999 7) within the range of 0. 04-0. 16 mg·mL-1. The RSD was 0. 52%with good repeatability. The detection limit was 2. 65 ng. Conclusion The method is accurate,reliable,sensitive and specific,which could be used for the determination of 3-amide-indolederivative and related substances.