The dependence on the vegetable diet in our existence will be suspected enough to switch to Sea-weeds. On the other hand, when Sea-weeds would become usual, the a㏄umulation of the minor minerals in our bodies should offer any influence on our health. That is to be studies hereafter. However, upt to now，the studies of these problems are not carried out; the reason seems to be in the fact that those studies are very very difficult, and require many troubles and endurance. The author studied on the Sea-weeds growing in the western district of the Japan Sea, of which he found the quantities of Cd(20-35)μg, Cu(0.12-0.20×10^<-2>)μg and Sr(250-580)μg in each one gram of ash respectively, measuring electrophotometrically with the reagents, 1-(2-Pyridylazo)-2-naphthol, dithizone and o-ctesolphthalene-complexone.