Essential oil of Piper betle leaves in Quang Nam-Da Nang do obtain via the steam distillation method with oil collection efficiency reaching 0.83%. The chemical composition of the essential oil from Piper betle leaves in Quang Nam-Da Nang is determined via the GC-MS method that includes 21 components (99.68%), among which the main components are eugenol acetate (32.33%), eugenol (24.56%), 4-allyl-1,2-diacetoxybenzene (19.8%), germacrene D (5.98%), caryophyllene (3.32%), and γ-muurolene (2.45%). The essential oil of Piper betle leaves in Quang Nam-Da Nang also showed moderate anti-acetylcholinesterase activity with IC50 (µg/mL) = 65.94±5.96 and moderate nitric oxide suppressing activity with IC50 (µg/mL) = 46.69±3.57.