The extraction of essential oil extracted from Eucalyptus globulus leaves in Southern Vietnam by microwave-assisted extraction (MAE) was investigated. The experimental study was conducted to determine the effect of different extracting parameters such as size of material, water to material ratio (1 mg/mL to 5 mg/mL), time (20 min to 80 min) and microwave power (100W to 600W). The essential oil content is determined by Gas Chromatography-Mass Spectrometry GC-MS method. The main ingredients of Eucalyptus globulus essential oils were Eucalyptol (38.771%). The highest essential oil content of 2.65 mg/L was achieved with the ground material, at the ratio of raw materials to water of 1: 3 mL/g, extraction time of 60 min, and microwave power of 450W. In conclusion, MAHD method is considered an efficient extraction process, saving time and cost of materials and heating.