The growth of suspension cultures of Taxus chinensis var. mairei and Taxol production were promoted both by a sinusoidal alternating current magnetic field (50 Hz, 3.5 mT) and by a direct current magnetic field (3.5 mT). Taxol production increased rapidly from the 4th d with the direct current magnetic field but most slowly with the alternating current magnetic field. The maximal yield of Taxol was 490 mug 1(-1) with the direct current magnetic field and 425 mug 1(-1) with the alternating current magnetic field after 8 d of culture, which were, respectively, 1.4-fold and 1.2-fold of that without exposure to a magnetic field.