Crude catechins extract from Chinese green tea were fractionated using Sephadex LH-20 column chromatography. The fraction containing (-)-epigallocatechin-3-gallate (EGCG) was then subjected to a semipreparative high-performance liquid chromatography (HPLC). Using a mobile phase of water: dimethyl formamide: methanol: acetic acid (157:49:2:1 v/v/v/v), the mixture of two methylated catechins was separated and isolated. According to mass spectrometry (MS) and nuclear magnetic resonance ('H-NMR) date, these compounds were identified as (-)-epigallocatechin-3-(3-O-methylgallate) and (-)-epigallocatechin-3-(4-O-methylgallate).