Abstract: To further study the biochemical characteristics of different cultivar of Camellia sinensis var. assamica in Yunnan, we analyzed 5 cultivars which had large planting area in Menghai, Yunnan and the catechin constituent content among different cultivars through detecting the content of tea polyphenol(TP), total catechins and main catechins. The results showed that all the 5 cultivars (Camellia sinensis var. assamica in Menghai,‘Dark Green Tea’,‘Yunkang No.10’,‘Yunkang No.14’and‘Changye-baihao’) had TP content more than 30%, and were 35.4%, 31.2%, 34.8%, 37.6% and 31.7% respectively. The total catechins content more than 20%, and were 24.5%, 26.2%, 29.7%, 32.3% and 22.7% respectively. In main catechins, ECG, EGCG and EC contents were higher, and the proportion of ECG and EGCG was larger, the contents of C, EGC and GCG were lower, and did not reach 0.5%. The catechins content of the 5 cultivars, the proportion of ester catechins (EGCG, ECG and GCG) was larger, it was between 54.49%-72.18% in TP, and between 76.53%- 84.58% in total catechins. On the whole, in all the 5 materials, the contents of TP and total catechins were higher, ester catechins was main catechin. However, the contents of TP, total catechins and main catechins (except GCG) had significant differences among different cultivars.