Objective:To find out the coefficients of garlic oil by Supercritical Fluid Extraction (SFE). Methods: Cutting, squeezing fermentation and fermentation and ethanol extraction of garlic were respectively as pretreatments and then the use of supercritical carbon dioxide as an extraction and given garlic oil was analysed by means of IR. Result: Garlic oil can be directly extracted by SFE and its best operation condition was under the pressure of 15 MPa and at 40 ?C extractability of garlic oil was up to 44.57% . Conclusion: Fermentation and ethanol extraction method is a best one for garlic oil obtained.