Abstract: In order to study the biochemical features that constituted tea quality differences of Fenghuang Dancong tea from different altitude ranges, the authors selected 5 Baxian Dancong mature tea gardens located at altitude of 300-1100 m in Chao’an County Fenghuang Town for study, made finished tea samples according to the same process, and conducted comparative analysis of biochemical composition of the finished tea and soil nutrient content differences from different altitude ranges. The results showed that differences of biochemical ingredients content between high mountain tea (elevation 800-1000 m) and medium mountain tea (elevation 500-700 m) were smaller. Content of tea polyphenols, tea pigment, caffeine, theobromine, gallic acid, theanine, aspartic acid, proline, glutamic acid and xylose, mineral elements of boron, zinc, iron, manganese, calcium, magnesium, copper and sulfur, and aroma components of hotrienol, trans-nerolidol, cis-jasmone, α-pinene, β-ionone, benzaldeh-yde, safranal etc. of high (medium) mountain tea were significantly higher than those of low mountain tea (elevation 300-400 m). Polyphenols, theaflavins, caffeine, theobromine, theophylline, gallic acid and aroma substances content such as alcohol, olefins, aldehydes, alkanes and esters were positively correlated with altitude. Soil nutrients and regional climate factor were the main reasons for the formation of Fenghuang Dancong tea quality regional differences. Soil of high (medium) mountain tea garden had higher organic matter content, nitrogen, phosphorus and potassium content were moderately balanced, and there were high mineral elements contents of calcium, magnesium, manganese, fluorine and selenium, indicating that soil properties were an important factor in the Fenghuang Dancong tea quality.