Abstract: To explore the volatile constituents of the early buds and old leaves at different temperatures,this paper analyzed the difference of odor between different Wu Niuzao tea leaves by electronic nose technique,and analyzed the volatile substances by GC-MS. The results showed that the electronic nose could quickly and effectively distinguish the new buds and old leaves at various temperatures,Principal Component Analysis(PCA)showed significant differences among samples. A total of 14,17,17,18 and 18 volatile substances were identified by GC-MS analysis in new buds that were untreated and subjected to heat treatment at 40,60,80,100℃,the main characteristic odorous ingredient was the alcohol substances such as linalool and nerol. A total of 21,21,19,18 and 27 volatile substances were identified in the old leaves after the same heat treatment,and the main characteristic odors were esters such as methyl salicylate.