This chapter reviews status, importance, biochemical composition, processing technologies and health benefits of green tea. Green tea indicates the tea that is prepared with the fresh green leaves of tea plant. The biochemical composition of green tea includes different constituents such as: protein and amino acids; fiber; carbohydrates; lipids; vitamins and anti-oxidants; pigments; volatile compounds; minerals; phenolic compounds (like polyphenols and flavonoids). Studies revealed that regular intake of green tea reduces the risk of oesophageal cancer (in Chinese population), lung cancer (in women), oral cancer (in Asian people), liver cancer (in Chinese and Japanese people). Freshly harvested young and unfermented leaves are immediately steamed to prevent fermentation, yielding a dry, stable product for producing green tea. High plasma cholesterol level is a big factor related to coronary heart disease can be reduced by consuming high level of green tea.