A new open-framework zinc phosphate, Zn 3 PO 4 (HPO 4 ) 3 .C 6 N 3 H 1 8 (denoted FJ-11), was synthesized under solvothermal conditions in the presence of 1-(2-aminoethyl)piperazine as structure-directing agent. Its structure was determined by single-crystal X-ray diffraction and further characterized by FTIR, elemental analysis, ICP analysis, powder X-ray diffraction and thermogravimetric analysis. The compound crystallized in the triclinic space group, P-1, with a=8.2807(2) A, b=9.13750(10) A, c=13.3463(2) A, α=83.7700(10) o , β=84.4460(10) o , γ=78.0250(10) o , V=979.17(3) A 3 , Z=2. The structure consists of ZnO 4 , PO 4 and HPO 4 tetrahedra with shared corners, forming intersecting three-dimensional channels. The triply protonated 1-(2-aminoethyl)piperazine molecules reside in the large 16-ring channels and interact with the inorganic framework by extensive hydrogen bonds.