In cell suspension cultures of Taxus chinensis, 40 mg/l fungal elicitor from Aspergillus niger and 20 microM HgCl2 elicited 5.7 and 3.6 mg/l taxol, which was a 9-fold and 5-fold increase vs. compared with the control, respectively. The fungal elicitor induced hydrogen peroxide (H2O2) accumulation but HgCl2 did not, indicating that H2O2 was not necessary for enhancement of taxol induced by elicitor. Compared with the treatment with fungal elicitor alone, exogenous catalase, ascorbic acid, diphenylene iodonium and superoxide dismutase induced a 0.45, 0.4, 0.7 and 1.4-fold H2O2, but elicited taxol production, which was 0.98, 1.2, 1.1 and 0.9-fold, respectively, vs. non-treated cells Elicitor-induced taxol production was not accorded with the amount of H2O2 production.