The objectives of this study were to investigate the distribution and chemical characteristics of cations in annual rings of Japanese cedar (Cryptomeriajaponica D. Don) grown in a healthy stand of an unindustrialized region in Japan and discuss the possibility of using cations in tree-rings as a chronological index of acidic deposition. Radial distributions of some cations and P at different vertical positions of the stem were analyzed for five trees from the same mountain. Each cation and P in all trees showed a specific distribution in its radial pattern but similar distribution trends were observed at all vertical positions. The cations and P were classified into three groups: (I) constant radial concentrations (Ca 2 + , Sr 2 +, Na ÷ , and probably Ba 2 +), (II) high concentrations in the heartwood and low in the sapwood (Mg +, K + , Rb ÷ , Cs +), and (IH) increasing concentrations in sapwood (P, Mn z ÷, Cũ +). The total concentration of cations exceeded the calcium-binding capacity (CBC) of the wood, and the excess was attributed to K + in a salt form. The CBC increased from the sapwood/ heartwood boundary toward the pith in the heartwood but remained constant in the sapwood. The increase of CBC in the heartwood was consistent with the profile of Mg 2+ , indicating a transfer of Mg + into heartwood and fixation on the acquired binding site. The radial distribution of 9°Sr was closely related to the cumulative deposition of fallout from the nuclear weapon tests, but that of ~TCs was unrelated. This suggests immobility of Sr~ + and mobility of Cs ÷ in the horizontal direction of wood. The conservation of the historical ~eSr/Sr2 + change indicated that no influence of heartwood formation on the chemical environment of Sr~+ in cedar xylem and a possibility of using Sr + as a chronological index of nutrient availability. A steady-state in nutrient availability is speculated for trees growing in this mountain because all of the trees analyzed show constant radial distributions of Sr 2 + for decades.