A coordination polymer with ordered and non-acidic water-duster guest molecules, [Zn(cis-chdc)(bpp)]center dot 6H(2)O (denoted as Zn-2-(H2O)(12), H(2)chdc = 1,4-cyclohexanedicarboxylic acid; bpp = 1,3-bis(4-pyridyl)propane), which captures a kind of (H2O)(12) cluster inside the cavity, is found to be an efficient proton conducting solid electrolyte. Zn-2-(H2O)(12) has a high conductivity of 0.241 mS.cm(-1) at 318 K and 95% RH (relative humidity), which is higher than the other kinds of water-only guested coordination polymers (CPs). The configuration of the water clusters has been described and the role it plays in the process of proton transportation has been investigated preliminarily.