1-(p-Methoxybenzyl)-2-(p-thoxyphenyl)-benzimidazole and 1-(p-hydroxybenzyl)-2-(p-hydroxyphenyl)-benzimidazole were snythesized by the condensation of o-phenylenediamine with p-methoxybenzaldehyde and p-hydroxyheozaldehyde under microwave irradiation,and characterized by melting point determination,elements analysis,IR and 1HNMR spectra.Antibacterial activities of the two benzimidazole derivatives were studied.