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.