The decatungstodivanadogermanic heteropolyacid H6GeW10V2O40-22H(2)O was synthesized for the first time by the stepwise acidification and the stepwise addition of solutions of the component elements. The product was characterized by means of inductively coupled plasma (ICP), IR, UV, X-ray diffraction and thermal analysis. The results of AC impedance measurement show that its proton conductivity is 1.20 x 10(-2) S.cm(-1) at room temperature (16degreesC).