Capillary zone electrophoresis (CZE) was adapted for the simultaneous determination of major components in green tea infusions. Separation was achieved using a fused-silica capillary column with a borax buffer at pH 8.0 and UV detection at 200 nm. The components analyzed were (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate, (-)-epigallocatechin gallate, (+)-catechin, caffeine, theanine and ascorbic acid. The concentrations of these components were significantly different among various kinds of teas. CZE can be a very useful tool to estimate the quality and taste of green tea.