Two 2-arylmethyl-1H-benzoimidazole compounds were synthesized by the reaction of o-phenylenediamine with 1-naphthylacetic acid or phenylacetic acid using a melting method,and their structures were characterized by IR and ¹HNMR spectra.The influences of the mole ratio of the reactants,the reaction time,the reaction temperature on the yield were investigated and optimum experimental conditions were found.Compared with the literature methods,this method has the advantages of simple operation,short reaction time,easy purification,less by-products,higher yield and green synthesis.