In different tea categories, the composition of these functional ingredients and content is not the same, the current drought from nru make tea flavor and the quality of their unique physiological effects. How to Choose dragon well tea?The unique quality of ingredients are green tea polyphenols, theanine, etc., the quality of ingredients unique tea theaflavins, thearubigins, etc.; tea categories such as tea Chahe factors, such as gallic acid, higher levels of. It is a hard job to select dragon well tea product.  Key words: green tea; black tea; Puer tea; theanine; caffeine; tea polyphenol (catechin); gallic acid. In order to obtain high quality longjing tea, we need to acquire huge amount of knowledge concerning it. Physiological effect on the quality and flavor, and theanine, caffeine and polyphenols are closely related components. Theanine is heavy and mellow tea taste characteristics as Bu shoot things in natural product extraction and utilization of people are divided on stone, dry bitter caffeine, polyphenols dry astringency, the composition of the three different flavors of tea quality is important impact. Whether the Dragon Well tea is good or not, we can identify it from the following four aspects, namely, the color, aroma, taste and shape of the tealeaves. Caffeine has excited nerves, hub effect, large doses of long-term use may cause side effects, but tea, the presence of caffeine because of its biological environment, make it right,}, in the central nervous effects than caffeine alone role to ease, which is tea, of theanine on, studies have shown that physical activity in the nerve, theanine significantly smaller antagonistic effect of caffeine on the LZ-3J. However, for normal tea drinkers, owing to that they could only observe the appearance and smell the aroma of the dried longjing tea leaves, it makes it harder to identify the tea products’ quality.In addition, pharmacological experiments show that the caffeine of tea catechins in the prevention of cancer and other effects have a synergistic effect. Then, how to choose high quality dragon well tea?  Green tea, black tea and tea in the domestic market) 'a popular tea category, respectively, not "ferment" full "fermentation" and the role of microorganisms in the post-"fermented" tea, tea leaf each with suitable varieties as raw materials production. High quality dragon well tea, as its name implies, is endowed with emerald green color, flat and straight shape.  The study looked at three types of tea, a representative of the West Lake Longjing, Biluochun, pray door black tea, Lipton tea and tea standard tender premium) and Lincang tea for the study, systematic analysis of the tea, of theanine, caffeine and tea polyphenols content and composition of relations, to explore the biochemical composition of these three kinds of different teas and related quality control and evaluation of dose-effect relationship between functional activity and group-activity relationship studies lay the foundation. dragon well tea infusion is light green, clear and bright.