Employed isophthalic acid and Quinoxaline as co-ligands, a new 3D metal-organic framework [{Cu 2 (IPT) 2 (QA) 2 } 6 ]n ((H 2 IPT= isophthalic acid, QA = Quinoxaline) had been prepared under hydrothermal condition. The compound crystallizes in the Rhombohedral space group R-3c, with cell parameters, a = 30.099(4) Å, b = 30.099(4) Å, c = 18.190(4) Å, a= β = γ = 90˚, V = 14271(4) nm 3 and Z = 12. This 3D complex based on rhomboid-shaped structural unit [{Cu2(IPT)2(QA)2}6] shows unusual USF-1 topology. On the basis of the results of TG/DTA analyses, the structure is thermally stable up to 300 °C.