To establish the evaluation method of Korean green tea, the correlation between physicochemical characteristics and sensory scores by the expert panels were investigated icing 15 hinds of green tea manufactured in 1985 from Korea, Taiwan and Japan. Tannin, caffeine and total free amino acid contents of Korean green tea are higher than foreign ones, but the chlorophyll content is the highest in Japanese high grade green tea. Sixteen free amino acids including theanine were identified, and theanine, glutamic acid, aspartic acid and arginine contents which affect the brothy taste of green tea infusion were highest in Korean green tea. Sensory score for the color of Korean green tea infusion were lower than Japanese tea, but the flavor and taste were she best. In multiple regression analysis, the quality affecting factors of the green tea were elucidated as the caffeine(X₁), chlorophyll b(X₂), total free amino acid contents(X₃), and L value(X₄) of green tea infusion. The regression equation was expressed as Y=-21.5820 + 2.1691X + 0.0130X₂+ 0.2314X₃- 0.0001X₄ and then R² was 0.8919.