A simple and efficient enzyme-assisted extraction procedure was developed and optimized for the extraction of paclitaxel and related compounds, namely 7-xyl-10-deacetylpaclitaxel, 10-deacetylpaclitaxel, cephalomannine and 7-epi-10-deaceylpaclitaxel from the needles of Taxus chinensis. The method was evaluated based on parameters such as enzyme type, pH and the concentration of the enzyme solution, incubation time and temperature. Statistical treatment of the results revealed that the selected parameters were all significant. Optimum conditions would be as follows: the needles were treated with 1 mg/mL cellulase solution, ratio of liquid to solid was 10: 1 (mL/g), and incubated at pH 4 for 24 h at 40 degrees C. Under the optimum conditions, the yields of paclitaxel, 7-xyl-10-deacetylpaclitaxel, 10-deacetylpaclitaxel, cephalomannine and 7-epi-10-deaceylpaclitaxel were 1.78-fold, 1.26-fold, 2.46-fold, 3.01-fold and 2.25-fold of those in the control, respectively. In addition, the effect of enzyme on the structural changes of plant cells was observed by scanning electron microscopy (SEM). Enzyme-assisted extraction was proved to be environment-friendly and economical, and could be used in natural product extraction in large scale. (C) 2009 Published by Elsevier B.V.