This paper summarizes the state of works have been studied by the Engineering Advancement Association of Japan and the results of the rear metal adsorbent experiments conducted in Okinotorishima-island and Iriomote-island. The adsorbents used in the experiments were developed by the National Institute of Advanced Industrial Science and Technology in lithium and by the Japan Atomic Energy Agency in uranium. The results of adsorbent efficiency in both lithium and uranium were mainly presented in this paper.