Tea is a widely-consumed beverage, and different types of tea can be produced depending on their oxidation levels. However, how different types of tea and brewing water temperature can affect health has not been considered. This investigation studied how compounds in tea such as caffeine, catechins, and L-theanine, were different in green tea, Bao Chong tea, and black tea, as well as in Bao Chong tea brewed with different water temperatures (25ºC, 45ºC, 75ºC, 90ºC) using NMR analysis. The results showed that Bao Chong Tea had the highest caffeine, catechins, and L-theanine content, followed by green tea and then black tea. The best temperature for brewing tea to produce caffeine, catechins and L-theanine was between 45ºC and 75ºC, and all chemical contents were reduced greatly at 90ºC. A better understanding of the relationship between tea and its chemical contents will allow people to have better knowledge of their food intake, and possibly allow people to choose accordingly.