A neutral octa-nuclear AuI-cluster (2) with molecular formula [(Cy-cAACPAu)4(AuCl)4] [Cy-cAAC =:C(N-2,6-iPr2C6H3)(C6H10)(CMe2)(CH2)] has been isolated, and structurally characterized by single-crystal X-ray diffraction. 2 has been further studied by NMR and ESI-MS. The μ3-P bridged AuI-cluster 2 possesses a C2 axis that passes through the two Au atoms positioned oppositely of the central Au(I)4P4 core, and two carbene-P chromophores. The emission spectrum of 2 exhibited a broad band with λem at 720 nm, and an average lifetime of 3.36 ns when excited at 388 nm in solid state at room temperature. Cyclic voltammetry (CV) studies revealed that 2 can undergo reversible one-electron oxidation at 0.76 V. The electronic transition in 2 has been further studied by computational methods.