Abstract: To determine the technical process and parameters of retting of ramie with enzymes in SC-CO₂some main environmental factors which can change the activities of pectinase and xylase are studied.The test shows that the optimal conditions for this enzymatic reaction in SC-CO₂are 45～50 ℃,8 MPa of the pressure of CO₂ pH 5～6.5,90 r/min and treatment duration of 1.5～2.0 h.Compared with traditional chemical retting,the enzymatic retting has the advantages of high fiber yield(increased by 14.3%) and good quality of single-fiber strength(increased by 10.5%).