In this study, the supercritical extraction from the seeds of Heracleum Persicum (Persian hogweed) using supercritical carbon dioxide was performed, and the yield of supercritical technology was compared with the hydro-distillation method. The experiments were examined in a laboratory scale apparatus at pressures of (15, 17.5 and 20 MPa), temperatures of (308, 318, and 328 ° K) , particles sizes of( 0.3, 0.5 and 0.7 mm) and the solvent flow rates of (1.2 * 10-5, 3*10-5, 4.8*10-5kg CO2/sec). The predicted model was based on the equilibrium between solid and solvent and included three parameters of mass transfer coefficient, axial dispersion coefficient, and the effective penetration coefficient that was in a good agreement with the experimental data. The extracted essential oil was analyzed by using gas chromatography (GC) and mass spectrometer chromatography (GC-MS) methods. After analysis of the extracted essential oil, hexyl butanoate, octyl 2- methyl butyrate, octylisobutyrate, and anethole were identified as the primary ingredients of the herb and the best test conditions were obtained. The extraction yield of supercritical technology was more than the Clevenger method. Therefore, supercritical fluid extraction is more selective than the hydrodistillation method.