The present paper involve prepared of heterocyclic compounds from salicylic acid. The first step synthesized of azo compound from p-phenylinediamine with salicylic acid.Then prepared Schiff bases from azo derivatives with benzaldehyde derivatives. The last step prepared Tetrazole derivatives from Schiff bases with sodium azide. These compounds were characterized by melting point. FTIR spectra and some derivatives by 1HNMR spectra,finally,the biological activity of the compounds were have been measured.