Abstract:Taxol, a diterpene with exceptional anticancer activity, occurs as a very minor component in several species of Taxus. By collecting the samples of 12 Taxus chinensis var. mairei trees of different diameters at breast height, the contents of taxol and 10\|deacetylbaccatin Ⅲ (10\|DAB) in the barks and 1\|year\|old needles were analyzed by UPLC. The average contents of the taxol and 10\|DAB were 0.0127 and 0.0805 mg?g-1 in 1\|year\|old needles and 0.1164 and 0.4842 mg?g-1 in barks, respectively. The contents of taxol in barks and 1\|year\|old needles had no correlation with tree diameter at breast height. The results of analysis on different modules (branches, needle, barks and roots) showed that the contents of taxol and 10\|DAB were highest (0.3527 mg?g-1) in roots, and the contents of taxol were lowest in 1\|year\|old needles (0.0096 mg?g-1). 10\|DAB was not detectable in 1\|year\|old needles. There were significant differences in the contents of taxol among 1\|year\|old needles, branches and roots. The contents of taxol and 10\|DAB in 1\|year\|old needles displayed significant seasonal variation. The contents of taxol and 10\|DAB of the needle from both natural and cultivated T. chinensis var.mairei all had a significant peak value in October when plants slowed down their growth.