Two novel high-symmetry 3D porous frameworks, [Cd-5(tetrazolate)(9)(OH)(H2O)](n).5nH(2)O (1) and [Cd-5(5-aminotetrazolate) (9)-(NO3)](n).3nH(2)O ( 2), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction analysis. The structures of 1 and 2 are characteristic of hexagonal tunnels through the trigonal-prismatic and hexagonal tubelike building units and exhibit their high stabilities of porous frameworks against the removal of the guest molecules.