Abstract: In this study, solvent-free microwave distillation approach was used for extraction of essential oil from leaves of Ledum plasture L. Effects of moisture content of raw materials, microwave irradiation time and microwave irradiation power on the yield of essential oil were investigated. The optimum extraction conditions were as follows: moisture content was 75%, microwave irradiation time was 30 min, and microwave irradiation power was 540 W. The chemical composition of the essential oil was analyzed by gas chromatography-mass spectrometry, and the main components were myrtenal (24.47%), lebaicone (12.51%) and 4-terpinenol (10.84%). Compared with traditional extraction methods, this method had the advantages of stability, high efficiency and energy saving.