An inorganic-organic hybrid compound, [H_3NC_2H_4NH_2]VOPO_4 was synthesized by means of the hydrothermal method. It was crystallized in a monoclinic system, a space group P2_1/c, with the crystal cell parameters: a=0.92285(11) nm, b=0.72994(9) nm, c=0.98495(11) nm, β=101.280(3)°, V=0.65067(13) nm~3, M_r=223.02 g/mol, D_c=2.277 g/cm~3, Z=4, R=0.0315, ωR=0.0865, GOF=1.085. The VO_5N octahedra chains are corner-linked by PO_4 tetrahedra; the VO_5N octahedra are all trans-linked with V—O bonds being alternately short and long. The monoprotonated ethylenediamine was intercalated between the layers with one end coordinating to V and the other end as an H-bond donor interacting with a terminal O atom of PO_4 from a neighboring sheet. The elementary analysis, infrared spectrum characters and thermal stability were also given. An inorganic-organic hybrid compound, [H_3NC_2H_4NH_2] VOPO_4 was synthesized by means of the hydrothermal method. It was crystallized in a monoclinic system, a space group P2_1 / c with the crystal cell parameters: a = 0.92285 (11) nm, b = 0.72994 (9) nm, c = 0.98495 (11) nm, β = 101.280 (3) °, V = 0.65067 (13) nm ~ 3, M_r = 223.02 g / mol and D_c = 2.277 g / cm ~ = 4, R = 0.0315, ωR = 0.0865, GOF = 1.085. The VO_5N octahedra chains are corner-linked by PO_4 tetrahedra; the VO_5N octahedra are all trans-linked with V-O bonds are alternate short and long. The monoprotonated ethylenediamine was intercalated between the layers with one end coordinating to V and the other end as an H-bond donor interacting with a terminal O atom of PO_4 from a neighboring sheet. The elementary analysis, infrared spectrum characters and thermal stability were also given.