Biodegradation pathways of taxol in cultured cells of Synechocystis sp. PCC 6803, Synechococcus sp. PCC 7942, Marchantia polymorpha, Nicotiana tabacum, and Glycine max were investigated using a water-soluble taxol derivative, 7-acetyltaxol-2"-yl glucoside, as the substrate. Although cyanobacteria, Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7942, and a lower plant, M. polymorpha, catalyzed the epimerization at 7-position of taxol skeleton, no epimerization occurred with higher plants, X tabacum and G. max. On the other hand, Synechocystis sp. PCC 6803, Synechococcus sp. PCC 7942, M. polymorpha, and N. tabacum catalyzed hydrolysis at 13-position of taxol to give baccatin III and 10-deacetyl baccatin III. Both cyanobacteria cells also deacetylated 7-epi-baccatin III at its 10-position. M. polymorpha and G. max deacetylated at 10-position of taxol.