A new charge-ordering (CO) state in quasi-1D iodide-bridged dinuclear Pt complexes (MMX-chains) was developed by introducing two different kinds of countercations. From crystal structure analysis, K-2(H3NCH2CHMeCH2NH3)[Pt-2(pop)(4)I]center dot 4H(2)O (pop = P2H2O52-) had structural features of both ACP (alternating charge-polarization) and CDW (charge-density-wave) states. Therefore, this new CO state was named ACP+CDW state. Remarkably, the structure was three dimensionally ordered, which was verified by the strong superlattice reflections observed in an X-ray oscillation photograph. Using polarized Raman and P-31 MAS NMR spectroscopies, it was shown that there were two different Pt-2 units and four inequivalent P atoms, respectively. These results agreed with the crystal structure analysis and supported the presence of the ACP+CDW state.