Elicitors and precursors were optimized for paclitaxel production in cell cultures of Taxus chinensis in the presence of nutrient feeding. The effects of nutrients feeding on cell growth and paclitaxel production were investigated initially and then response surface methodology (RSM) was used to optimize the concentrations of several precursors and elicitors for paclitaxel production in the presence of nutrient feeding. In the first step, the effect of silver nitrate, abscisic acid, chitosan, phenylalanine, methyl jasmonate, sodium benzoate and glycine was evaluated using a fractional factorial design. The major factors proved to be methyl jasmonate, chitosan, and abscisic acid. The effects of these main factors were further investigated by a central composite design. Paclitaxel production reached 54 mg l(-1) when 10 mg l(-1) silver nitrate, 6 mg l(-1) abscisic acid. 23 mg l(-1) chitosan, 15 mg l(-1) phenylalanine, 31 mg l(-1) methyl jasmonate, 30 mg l(-1) sodium benzoate and 30 mg l(-1) glycine were added on day 12 together with feeding solution containing 20 g l(-1) sucrose added on day 16, which was 2 times higher than paclitaxel 9 production without optimization. (C) 2003 Elsevier Ltd. All rights reserved.