Two transition-metal-substituted compounds K10H10{[Co(H2O)(2)](2)[Co(H2O)(3)](2) (Ge4W36O130)}center dot 32H(2)O (1Co) and K10H10{[Ni(H2O)(2)](2)[Ni(H2O)(3)](2) (Ge4W36O130)}center dot 32H(2)O (2Ni), have been successfully synthesized, both of which consist of the S-shaped tetrameric structure {Ge4W36} constructed from trivacant Keggin-type germanotungstate precursor K8Na2[A-alpha-GeW9O34]center dot 25H(2)O. These compounds were characterized by single crystal X-ray diffraction crystallography, X-ray powder diffraction (XRD), Raman spectra, thermogravimetric analysis (TGA), electrochemistry, and IR spectra. In addition, the UV spectra and the electrospray-ionization mass spectra (ESI-MS) were employed to investigated the stable pH value range of 1Co and 2Ni in aqueous solution.