Optimization of extraction conditions for fucoxanthin from brown algae Eisenia bicyclis was investigated through a pressurized liquid extraction (PLE) method and statistical experimental design. The process was optimized by Plackett-Burman design at first step to screen the most important variables in the extraction of fucoxanthin, and subsequently central composite design was applied to attain the optimum conditions of the selected factors for fucoxanthin extraction. Two factors, temperature and ethanol concentration, significantly influenced the extraction efficiency of fucoxanthin at 95% level (P<0.05). The maximum predicted value of fucoxanthin extraction was 0.42 mg/g at 110 degrees C and 90% ethanol. The validation of the model was verified by triplicate experiments under the optimal conditions. The results demonstrated that the statistical strategy was successfully applied for optimization of PLE method for fucoxanthin extraction and that PLE can be a powerful method to extract fucoxanthin from E. bicyclis. (C) 2010, The Society for Biotechnology, Japan. All rights reserved.