Abstract: A series of bis(2,4-diamino-quinazol-6-yl-substituted aminomethyl) aromatic derivatives were synthesized. Compounds Ⅱ_1～5 were synthesized by two ways. In the first, 2,4,6-triaminoquinazoline was condensed with the corresponding aryl dialdehydes to form Schiff bases which were reduced with sodium borohydride; the second used a new method in which 2,4,6-triaminoquinazoline was directly condensed with the corresponding aralkyl dihalides to afford the same products. The derivatives Ⅱ_6～16 were prepared by formylation, nitrosation or methylation respectively.The inhibition activities of the title compounds on dihydrofolate reductase in rat liver were assayed. The activities of formylated or nitrosated products were 6-9 times, and of methylated products were twofold as active as that of the parent compounds. Ⅱ₆, Ⅱ₉, Ⅱ₁₀ and Ⅱ₁₄ were nearly as potent as pyrimethamine. Primary antimalarial screening in mice showed that no one possessed significant activity.