This article studied the effects of the treatment of filling nitrogen in vacuum and decaffeinating with boiling water on quality of green tea. Results showed that the two processing technologies could change the constitution of the volatile components significantly, causing a series of change on tea color, aroma, flavor, and constitution of functional components. After filling nitrogen in vacuum singly, the flavor acceptance of tea sample decreased, the comparative content of volatile compound decreased 39%, 27 kinds of detectable volatile compounds and alcohols decreased;the percentage of acid, furan and other volatile compound increased. Compared tea samples after filling nitrogen in vacuum and decaffeinating with boiling water to tea samples after filling nitrogen in vacuum singly, the comparative content of 55 kinds of volatile compounds were decreased, the comparative content of 28 kinds of volatile compounds increased, the total content of volatile compound decreased 56%. The percentage of acid, furan in the tea samples with filling nitrogen in vacuum and decaffeinating with boiling water are lower than those with filling nitrogen in vacuum singly, the flavor acceptance are also improved .These indicated that the process of decaffeinating with boiling water can improve the functional constitution and flavor acceptance of the GABA tea products.