Abstract: HPLC was applied to the determination of 7-methoxy-1-naphthyl-acetonitrile (MONAN),which is an important intermediate in the preparation of anti-depression drugs.The Diamonsil C18 chromatographic column (250 mm×4.6 mm,5 μm) was used as stationary phase for separation of MONAN from co-existing by-products and impurities at column temperature of 20 ℃.A mixture of methanol and H2O (80+20) was used as mobile phase with flow-rate of 0.8 mL·min-1.UV-detection was made at the wavelength of 231 nm.Volume of sample solution introduction was 20 μL.Linear relationship between values of peak area and mass concentration of MONAN was obtained in the range of 2-48 mg·L-1.Detection limit (3S/N) found for the method was 105 μg·L-1.Precision and recovery were tested at the concentration level of 40.0 mg·L-1 of MONAN for 6 determinations,value of RSD and average recovery found were 0.034% and 99.7% respectively.