For the safety assessment of radwaste treatment and disposal, the leaching characteristics of $Cs^+;and;Sr^{++}$ from the cement-solidified radwastes was investigated by means of the survey and analysis of the activity leach rate and cumulative leach fraction of $^{137}Cs;and;^{90}Sr$ leaching from solidified radwastes. The cylindrical cement-solidified samples were made by the sodium silicate method and neutralization method changing the mole density of simulated liquid radwaste, type of cement, adding material and concentration of boric acid. The leaching study was carried out by the method using simulated PWR concentrated liquid radwaste solidified in cement that had been processed following the recommendations of IAEA. All the experimental results are in well accordance with the research data reported previously, but the watertight cement-solidified radwastes show rather high leach rate of radioactivity. It is learned, therefore, that the watertight cement is not adequate as the material for the solidified radwastes.