The title compound (C6N3H18)(2)Ti4O4(C2O4)(7)(.)4H(2)O 1 (C13H22N3O18Ti2, M-r = 604.14) was synthesized by the reaction of Ti(SO4)(2), H(2)C(2)O(4)(.)2H(2)O and N-(2-ammonioethyl)piperazinium (AEPP) in aqueous solution. The single-crystal X-ray analysis has revealed that I crystallizes in the triclinic system, space group P (1) over bar with a = 9.1437(6), b = 11.4991(10), c = 11.6975(8) Angstrom, a = 96.2915(18), beta = 107.998(3), gamma = 104.276(4)degrees, V = 1110.35(14) Angstrom(3), Z = 2, D-c = 1.807 g/cm(3), F(000) = 618, mu = 0.815 mm(-1), the final R = 0.0463 and wR = 0.1264 for 3718 observed reflections with I > 2sigma(I). X-ray crystal-structure analysis suggests that compound I consists of [Ti4O4(C2O4)(7)](6-) anion and two protonated N-(2-ammonioethyl)piperazinium cations. The anions are linked into an infinite chain through Ti4O4(C2O4)(8) by sharing the oxalates as bridging ligands.