The concentrations of the five main catechins (flavanols), epigallocatechin gallate, epicatechin gallate, epigallocatechin, epicatechin, catechin and four main theaflavins, theaflavin, theaflavin-3′-gallate, theaflavin-3-gallate, theaflavin-3,3′-digallate in black tea brew and their effects on astringency were investigated. The catechins and theaflavins were assayed by HPLC. Astringency, which was scaled from 1 to 9, was estimated by a trained panel. The correlations between astringency and content of total catechins and individual catechins, except catechin itself, were significant, whereas no correlation between theaflavins and astringency was observed.