New proton conducting polymers based on poly(silamine) (PSA) were synthesized by complexing the polymer and H 3 PO 4 , and the proton conduction of these materials was investigated. The PSA/H 3 PO 4 complex was thermally stable up to 200 o C, as indicated by TG/DTA analysis. The conductivity of 10 - 5 S cm - 1 was observed at 160 o C for anhydrous PSA/H 3 PO 4 complexes with a concentration of 0.8 H 3 PO 4 per repeat unit. The carrier ion was proven to be proton on the basis of the H/D isotope effect on conductivity for PSA/H 3 PO 4 and PSA/D 3 PO 4 complexes.