Abstract: The microwave-assisted steam distillation extraction of essential oil from Artemisia argyi leaves was optimized for achieving maximum oil yield by response surface methodology based on single factor experiment.And chemical composition of the extracted oil was analyzed by gas chromatography-mass spectrometry(GCMS). Their total content was determined by the area normalization. The optimal conditions for oil extraction were found as follows:microwave power was 480 W,irradiation time was 94 s liquid-material ratio 5∶1,distillation duration 2.2h,and concentration of Na Cl was 5%. The resultant oil yield was up to 2.58mg/g. The main compouds were 3-Cyclohexen-1-ol,4-methyl-1-(1-methylethyl)-(18.75%),Selina-6-en-4-ol(11.74%),Eucalyptol(9.10%),Caryophyllene oxide(8.01%),2-Cyclohexen-1-ol,2-methyl-5-(1-methylethenyl)-cis-(6.27%),3,3,6-Trimethyl-1,4-heptadien-6-ol(5.21%). It turned out that the selected process conditions was feasible by the verification test.