Abstract: To explore the quality characteristics of Chongqing congou, one bud with two leaves of Sichuan groups was selected as raw material to process with Chongqing congou technologies, and changes of main biochemical components and aroma components during processing were analyzed. The results showed that the contents of water extracts and tea polyphenols went a downtrend;contents of free amino acids, soluble sugars and caffeine went upwards first then decreased to a stable level;contents of tea pigments increased significantly to a stable level during withering and fermentation. According to headspace solid phase microextraction and gas chromatography-mass spectrometer analysis, 58 kinds of aroma were detected during the process of Chongqing congou, including 15 kinds of alcohols, 12 kinds of esters, 16 kinds of terpenes, 5 kinds of aldehydes, 5 kinds of ketones and 5 others, and the contents of alcohols (23.52%~52.08%) and esters (29.29%~61.73%) were far more than the others. Besides, contents of linalool and its oxidation (2.87%~21.36%), geraniol (1.92%~15.14%), phenethyl alcohol (4.83%~7.11%), hotrienol (0.24%~5.16%), methyl salicylate (11.44%~56.25%), δ-cadinene (0.62%~4.56%) were comparatively higher. In addition, linalool and its oxidation might dominated the aroma type of Chongqing congou.