1.lifen;2.College of Tea（Pu’er）， West Yunnan University of Applied Sciences;3.Tea Research Institute，Yunnan Academy of Agricultural Science;4.(1. College of Tea（Pu’er）， West Yunnan University of Applied Sciences
The objective of this study is to explore the seasonal variation of biochemical components content of different cultivars of Camellia sinensis var.assamica in Yunnan,and the influence of on cultivars and season on the biochemical components of tea, which is informing for the selection of cultivars and picking season of tea. 5 cultivars of Camellia sinensis var.assamica cv.Yunkang10, Camellia sinensis var.assamica cv.Yunkang 14, Camellia sinensis var.assamica cv.Xueya100, Camellia sinensis var.assamica cv.Foxiang2 and Camellia sinensis var.assamica cv.Zijuan were chosen as the research object. One bud and two leaves of the new shoot were sampled and steamed in spring, summer and autumn, respectively. To examine the seasonal variation of main biochemical components content of tea, and compare the biochemical components content of these 5 cultivars, water content, water extract, tea polyphenols, amino acids, caffeine and catechin components of (+)C、EC、EGC、ECG and EGCG of samples were measured. The results showed that: ①The content of total catechin of Camellia sinensis var.assamica cv.Zijuan was significantly higher than other cultivars, which was contributed by its EGC and EGCG contents. ② The highest content of water extract, amino acid and catechin quality index were in Camellia sinensis var.assamica cv.Yunkang10. ③ The tea sampled spring had the highest content of amino acid, which was even higher than the threshold value of famous green tea；④ The tea sampled in summer had significantly higher content of water、caffeine、(+)C and the total of catechin than in other seasons；⑤ The tea sampled in autumn had the highest content of tea polyphenols, while the lowest contents of the total of catechin and amino acid. Therefore, we concluded that the biochemical components of tea showed significant differences among different cultivars and different seasons, It was indicted that the differences of biochemical components and practices should be combined to study the suitability of tea.