Objective: To optimize supercritical carbon dioxide fluid extraction (SFE-CO2) process of volatile oil from the roots of Clematis chinensis

and components of volatile oil were analyzed by GC-MS. Method: With yield of volatile oil as index

effects of extraction time

particle size of raw materials

fluid extraction pressure and temperature on SFE-CO2 process of volatile oil from the roots of C. chinensis were investigated by single factor test and orthogonal test

and chemical constituents of volatile oil were analyzed by GC-MS. Result: Effects of three factors on yield of volatile oil were in order of extraction pressure>extraction time>extraction temperature;Optimal fluid extraction technology was as following:extraction pressure 20 MPa

extraction time 1.5 h

temperature 45 ℃;Yield of volatile oil under these conditions was 0.44%.156 compounds were identified by GC-MS and they were accounting for 85.03% of the total content of volatile oil

compositions that the relative content was more than 1% accounted for 51.78% of the total content of volatile oil. Conclusion: SFE-CO2 method had higher extraction efficiency than steam distillation

this optimized technology was stable and reliable.In addition

chemical compositions of volatile oil were complicated

and protoanemonin

the major bioactive component in volatile oil from the roots of C. chinensis

was found by GC-MS for the first time.