Objective:To investigate the relationship between the amount of water-soluble components of gastrodia and the boiling time. Method: A phenomenex C18 (4.6 mm×250 mm

5 μm) column was adopted. The mobile phase consisted of acetonitrile (A) and 0.2% phosphoric acid solution (B) in gradient elution mode. The flow rate was 1.0 mL·min-1. The detection wavelength was set at 220 nm. Result: The linear range of gastrodin was 0.354 4-3.544 μg (r>0.999). The average recovery was 99.4%

RSD 1.2%. The maximum amounts of six major components including gastrodin were decocted 3 hours. Conclusion: The best time of decoction of Gastrodiae Rhizoma was 3 hours

consistent with traditional requirements.