In succession of the paper1) reported in 1960, the measurements of strontium-90 (Sr-90) and cesium-137 (Cs-137) concentrations in milk powder were carried out in order to investigate the extent of the later radioactive contamination of milk in Japan. Whole-and skim milk powders collected from several localities of the whole country every season from 1958 to 1962 were used for radioactivity assay. These experiments show that there is regional produced in Japan is higher than that of other countries.