whereas comprehensive study on chemical compositions associating with colour, taste, aroma and other essential features of this type of tea is relatively limited. Most studies used samples either of specially produced official reference with known quality ranks (Nakagawa et al., 1981; Chen et al., 1985; Liu et al., 1987) or of wide origins or categories with inherently different quality characteristics because of considerable deviations in growth conditions, harvesting seasons, maturity of harvested shoots and the processing technologies (Mukai et al., 1992; Le Gall et al., 2004). A wide origins or categories of tea samples within single investigation could make quality ranking rather complicated as special parameters or standards may be required for specific teas. In this study, Longjing tea was selected as a model for green tea to explore the relationship of chemical components with the perceived quality index assessed by sensory evaluation. All the Longjing tea samples were taken directly from farmers of core production area to ensure that they were harvested in a single spring season at similar maturity and similarly processed by hand.