To better understand protonic conduction of perovskite-type oxides based on SrCeO3, BaCeO3, CaZrO3 and SrZrO3, their TPD spectra were measured. By estimating the amount of water vapor evolved from these oxides, proton concentrations were found to be smaller in the order SrCe0.95Yb0.05O3-alpha, BaCe0.95Y0.05O3-alpha, SrZr0.95Y0.05O3-alpha and CaZr0.9In0.1O3-alpha. Peak maximum temperatures gave the order of proton mobilities as: BaCe0.95Y0.05O3-alpha > SrZr0.95Y0.05O3-alpha > CaZr0.9In0.1O3-alpha > SrCe0.95Yb0.05O3-alpha. Protonic conductivity could be explained by these two orders.