Medicinal plants are a potential source of enzyme acetylcholinesrerase (AChE) inhibitors, a key target in the treatment of Alzheimer’s disease. This paper studies the AChE inhibitory activity and the antioxidant effect of Persea Americana Mill extract. The sample leave, seed, exocarp and mesocarp of avocado were extracted with 50% ethanol and subsequently fractionated with n-hexane, ethyl acetate (EtOA) and n-butanol (n-BuOH) solvents. The AChE inhibitory activity was evaluated by Ellman’s colorimetric method and the antioxidant activity by screening DPPH free radicals. The results show that the seed of Persea Americana extract had the strongest AChE inhibitory activity and antioxidant effect, followed by the leave extract, and the exocarp extract and mesocarp extract were the weakest. The Persea Americana seed extract inhibited AChE activity in a dose-dependent manner with an IC50 value of 47.43 ± 0.5 μg/mL and the antioxidant effect with an IC50 value of 68.7 ± 0.35 µg/mL. The results also show that n–BuOH fraction of Persea Americana seed extract had strong AChE inhibitory and antioxidant activities with an IC50 value of 15.24 ± 0.52 µg/ml and 15.73 ± 0.42 μg/mL, respectively. The study results suggest that the Persea Americana Mill is a promising ingredient in Alzheimer’s disease prevention and treatment. Keywords Persea Americana Mill, Acetylcholinesrerase inhibitors (AChE), Alzheimer, DPPH. References [1] M.M. Essa et al., Neuroprotective effect of natural products against Alzheimer's disease, Neurochem Res. 37(9) (2012) 1829.[2] B. McGleenon, K. Dynan, A. Passmore,. Acetylcholinesterase inhibitors in Alzheimer's disease, British journal of clinical pharmacology. 48 (1999) 471.[3] P. B. Watkins et al, Hepatotoxic effects of tacrine administration in patients with Alzheimer's disease, In: Jama. pp. 992 (1994).[4] O. Adeyemi, S. Okpo, O. Ogunti,. Analgesic and anti-inflammatory effects of the aqueous extract of leaves of Persea americana Mill (Lauraceae). In: Fitoterapia. pp. 375 (2002).[5] P.D.D. Dzeufiet, et al, Antihypertensive potential of the aqueous extract which combine leaf of Persea americana Mill. (Lauraceae), stems and leaf of Cymbopogon citratus (DC) Stapf.(Poaceae), fruits of Citrus medical L.(Rutaceae) as well as honey in ethanol and sucrose experimental model. In: BMC complementary and alternative medicine. p. 507 (2014).[6] B.I. Brai, A. Odetola, P. Agomo,. Hypoglycemic and hypocholesterolemic potential of Persea americana leaf extracts, Journal of medicinal food. 10(2) (2007) 356.[7] Phạm Khuê. Bệnh Alzheimer. Nhà xuất bản Y học (2002).[8] Đàm Trung Bảo. Các gốc tự do, Tạp chí Dược học. 6 (2001) 29 [9] F.R. Mowsumi, A. Rahaman, N.C. Sarker, B.K. Choudhury, S. Hossain, In vitro relative free radical scavenging effects of Calocybe indica (milky oyster) and Pleurotus djamor (pink oyster), World J Pharm Pharm Sci. 4(07) (2015) 186.[10] Y. Bao, Y. Qu, J. Li, Y. Li, X. Ren, K....