As baccatin Ⅲ is an immediate diterpenoid precursor of taxol, the increase of baccatin Ⅲ is beneficial to the biosynthesis of taxol. Addition of methyl jasmonic acid (M J) enhances the activity of 10- deaceyle baccatin (DAB) Ⅲ acetyl transferase which catalyzes the bioconversion from 10-DAB Ⅲ to beccatin Ⅲ. In this paper, the baccatin Ⅲ content was increased by 174% by the addition of 100 μmol/L MJ in suspension cultures of Taxus cuspidate. Induction by MJ also increased the expression of a 49.0-kDa protein. This paper describes the cell free acetylation of 10-DAB Ⅲ in crude extracts of enzyme from the suspension cultures of Taxus cuspidate. The reaction product was confirmed by high performance liquid chromatograph (HPLC). About 25.0% of the 10-DAB Ⅲ was acetylized into baccatin Ⅲ on the 4th day with 100 μmol/L MJ.The 10-DAB Ⅲ acetyl transferase activity reached a peak on the 2nd day with 100 μmol/L M J, with 54.7% of the 10-DAB Ⅲ transformed into baccatin Ⅲ. The baccatin Ⅲ content increased with the increase of 10-DAB Ⅲ acetyl transferase activity, although the biosynthesis was delayed by more than 24 h. The remarkable induction of MJ on baccatin Ⅲ biosynthesis shows a promising way to increase the production of taxol.