Novel synthesis method of aromatic hydrazine by use of benzotriazole was reported. At first, the intermidates 1-arylformylbenzotriazoles were synthesized by reaction of benzotriazole and aromatic acid. And then, the aromatic hydrazines were prepared by hydrazinolysis of 1-arylformylbenzotriazoles with hydrazine hydrate, which was recrystallized with acetonitrile-trichloromethane, the yield of the product was more than 90%. The structure of the title compound was characterized by melting point, IR and1H NMR spectra.