In this study, a systematic method was used to optimize the supercritical fluid extraction (SFE) of ligustilide in Ligusticum chuanxiong Hort. Overall five variables (pressure, temperature, static extracting time, modifier concentration and CO2 dynamic extracting volume) were considered. To reduce the loss of volatile substance, a solid-liquid trap was developed for SFE collection. Comparisons were made on the solvent trap for SFE. The extracts were analyzed by high performance liquid chromatography (HPLC) with ultraviolet absorbance detection. The recoveries of 99.34% (RSD 1.70%) and 92.11% (RSD 5.72%) were achieved for solid-liquid trap and solvent trap, respectively. SFE conditions: temperature 40 degrees C, pressure 27.6 MPa, static extraction 3 min, dynamic extraction 7 ml and 0.1 ml CHCl3 as modifier. HPLC conditions: The HPLC column (3.9 mm x 150 mm) was packed with Nova-Pak C18(4 microns). Naphthalene was used as internal standard. The mobile phase was methanol--10% isopropyl alcohol solution (53:47 v/v). The detection wavelength was 280 nm and the flow rate was 0.8 ml.min-1.