HPLC-ELSD method for the determination of astragaloside IV in Longdan Tongluo Capsule was established. YMC-Pack ODS-A column (4.6 mm × l50 mm. D. S-5 μm) was used with mobile phase of acetonitrile-water (35:65, volume/volume), flow rate was 1.0 mL/min, column temperature was 30°C, drift tube temperature of 110°C, the flow rate of carrier gas was 2.5 mL/min. The results showed that linear range of astragaloside IV in 2.032-20.32 μg, the correlation coefficient was 0.99912, the average recovery rate was 98.79%, RSD was 0.96% (n=6). The method was simple, accurate, reproducible, suitable for determination of astragaloside IV in Longdan Tongluo Capsule.