Seed oil was extracted from lagerstroemia speciosa with supercritical CO2. Extraction rate was measured as a function of pressure, temperature, flow rate, and particle size. The results of the experiments indicate that the optimum extraction pressure, temperature, particle size and CO2 flow for the maximum traction was 30Mpa,40℃,40mesh,12kg/h respectively. The components of seed oil was determined by GC- MS. Total 12 fatty acids were determined out. The content of linoleic acid was 74.57%. Branched chain acid and odd number carbon acid were first determined out in lagerstroemia speciosa seed oil.
