A packaged beverage with a green tea extract mixed therein, which contains (A) a non-polymer catechin, (B) oxalic acid or a salt thereof, and (C) caffeine, where the content weight ratio (B)/(A) is from 0.00005 to 0.1, and the content weight ratio (A)/(C) is from 5 to 10000. The packaged beverage contains catechins at high concentration, is reduced in bitterness and astringency and is suited for long-term drinking, is excellent in the stability of bitterness and astringency and also in the feeling as it passes down the throat, and further, remains stable in its color tone even when filled in a clear container and stored at high temperatures.