Three diterpenes were isolated from the bark of T. mairei collected in Fujian Province of China. Taxamairin A (I), B (II) and C (III) were proved to be new diterpenes. Thus, I and II are tricyclic-diterpenes containing a tropone ring system, while III is a tetracyclic-diterpene bearing a hemiketal moiety. These structures were elucidated by high resoln. 1H NMR, 13C NMR DFNOE and 1H-1H COSY. The structure of I was confirmed by x-ray diffraction anal.

Key words: ANTICARCINOGEN, INFRARED SPECTROPHOTOMETRY, X-RAY DIFFRACTION ANALYSIS, C13 NMR SPECTROMETRY, PROTON MAGNETIC RESONANCE SPECTROMETRY, DITERPENE ALKALOID, TAXACEAE, STRUCTURAL ANALYSIS, TRICYCLIC DITERPENE, TETRACYCLIC DITERPENE