The Chinese drug Tian-Ma(Gastrodica elata Bl.) was extratted with petroleum ether and followed by 70% ethanol.These two extracts were then passed through the silica columns separately and eight constituents were thus obtained.The main pomponent of the ethanolio extract, Ⅶ under the name of gastrodin is a phenolic gluooside.Gastrodin, C₁₃H₁₈O₇ was obtained as colorless prismatic crystals, m.p, 145-148℃,[α]_D¹⁵-66.4°(C·0.65 H₂O).On the basis of spectrometric data (NMR, MS, UV, IR),enzymatic hydrolysis and the properties of its derivatives, the structure of gastrodin is assigned as p-hydroxymethylphenyl-,B-D-glucopyronoside (VII).Other seven components were identified as p-hydroxybenzyl alcohol (Ⅲ),aglycono of gastrodin; β-sitosterol (Ⅱ) and its D-glnooside daucosterol; citric acid (Ⅴ) and its symmetrical monomethyl ester (Ⅳ); palmitio acid (Ⅰ) and sucrose (Ⅷ) respectively.