A new two-dimensional zinc phosphate [Zn-2(HPO4)(3)](2-)[(C6N4H22)(0.5)](2+) has been prepared hydrothermally by using triethylenetetramine (tetam) as the structure-directing agent. The structure of the compound was solved by single-crystal X-ray diffraction analysis. [Zn-2(HPO4)(3)](2-)[(C6N4H22)(0.5)](2+) crystallizes in the triclinic space group P (1) over bar (no. 2) with a = 7.4876(8) Angstrom, b = 8.2336(8) Angstrom, c = 12.8592(13) Angstrom, alpha = 98.723(2)degrees, beta = 101.258(2)degrees, gamma = 115.785(2)degrees, Z = 2, and V = 674.51(12) Angstrom(3). The structure consists of macroanionic sheets stacked in an AAAA sequence. As primary building units in the individual sheet, alternating PO4 tetrahedra with terminal -OH groups and "unsaturated" =O atoms and ZnO4 tetrahedra are linked together to form elliptical twelve-membered rings as well as four-membered rings. These macroanionic sheets are held together by strong hydrogen bonding.