Abstract: For the purpose of improving the oral antimalarial activities of the fluorenemethanols (reported by us in previous articles) which were less effective by oral than by subcutaneous administration, 24α-(alkylaminomethyl)-2,7-dichloro-9-substituted benzylidene-4-fluorenemethanols (III) were synthesized. The results of preliminary screenings demonstrated that five compounds (No.1～4,8) exhibited significant antimalarial activities against Plasmodium berghei NK₆₅ strain in mice by oral administration, at dose of 6.25 mg·kg^-1·d^-1×3 with suppressive rate of 100%. Further evaluation of these 5 compounds showed that 4 of them (No.1～4)were superior to chloroquine in parallel tests, their ED₅₀ and ED₉₀ were 1.0, 1.6; 0.6, 0.9; 0.7, 1.5 and 0.8, 1.6 mg·kg^-1·d^-1×3 respectively, while the ED₅₀ and ED₉₀ of chloroquine were 1.9 and 2.9 mg·kg^-1·d^-1×3 respectively; one compound (No.8) was equal to chloroquine, its ED₅₀ and ED₉₀ were 1.5 and 3.2 mg·kg^-1·d-1×3 respectively. Further assessment of these 4 compounds are in progress.