An investigation of the indole alkaloids of Haplophyton crooksii has resulted in the identification of two new alkaloids-10-methoxy-N1-methylpericyclivine (1) and 16-decarbomethoxyvinervinine (2)-and 13 known alkaloids-crooksiine, yohimbine, beta-yohimbine, crooksidine, decarbomethoxytetrahydrosecodine, akuammicine, tubotaiwine, lanceomigine, lanceomigine N-oxide, haplophytine, cimicine, cimicidine, and akuammidin-as major alkaloids of this shrub. All of the isolated alkaloids showed an inhibition of acetylcholinesterase activity in vitro.