Abstract: Supercritical CO₂ fluid extraction (SCFE) was optimized by response surface method (RSM) to study the utilization of flowers of Nicotiana tabacum in tobacco, spice and medicine, etc. Taking the extraction yield of flowers of Nicotiana tabacum as response value, the effects of technical conditions on the extraction yield were determined by designing experiments according to Box-Behnken Design (BBD). The volatile components in the extract were identified by GC/MS method. The results showed that:1) The optimal extraction conditions were:pressure 31.9 MPa, temperature 47.3℃, and time 108.5 mins. 2) 28 components were identified, and their contents were determined with peak area normalization method, among them, the component with the highest content (43.81%) was 1, 5, 9-trimethyl-12-(1-methylethyl)-4, 8, 13-cyclotetradecatriene-1, 3-diol.