The localization of paclitaxel was investigated in suspension culture cells of Taxus chinensis. Over 93% of the cell-associated paclitaxel were detected throughout the entire culture period. Intracellular localization of paclitaxel over the culture time was analyzed further by cell fractionation for days 21 and 42. Paclitaxel contents in intracellular organelles were decreased at day 42, while the content in the cell wall fraction was increased at day 42 compared to the value for day 21. The localization of paclitaxel in the cell wall was confirmed by using the immunocytochemical method with the aid of a confocal laser scanning microscope.