[en] We studied the sorption behavior of Sr onto calcium-silicate-hydrates (C-S-H), calcium-aluminate-hydrates ettringite (AFt), monosulphate (AFm), and hydrogarnet (C₃AH₆) by applying a sequential desorption method. The results showed that: The distribution coefficients (K_d) of Sr sorption onto C-S-H increased with decreasing Ca/Si ratios of C-S-H. This K_d change is explained with the zeta potentials of C-S-H at various Ca/Si ratios and with the change of surface functional group, Sr is sorbed on C-S-H through plural sorption forms. The observation that some Sr is desorbed by EDTA and nitric acid suggests that a replacement of Ca with Sr takes place in the C-S-H structure, and Sr is structurally incorporated into AFt, AFm, and C₃AH₆. (orig.)