Based　on　the　molecular　dynamics　simulation,the　effects　of　four　cations(K+,Na+,Ca2+,Mg2+)on　the　diffusion　behavior　of　chloride　ions　in　the　calcium　silicate　hydrate(C-S-H)pores　were　investigated.　It　is　found　that　adsorption　capacity　of　C-S-H　for　chloride　ions　is　related　to　its　adsorption　capacity　for　cations.　Ca2+　and　Mg2+　can　promote　the　adsorption　of　chloride　ions,and　the　desorption　of　surface　calcium　in　C-S-H　can　be　easily　facilitated　into　the　solution,in　which　the　spatial　correlation　between　chloride　ions　and　pore　water　is　prolonged,resulting　in　the　presence　of　multiple　layers　of　hydration　shells　around　chloride　ions　and　the　reduction　of　the　diffusion　ability.　Under　the　combined　actions　of　cations　attracted　by　the　C-S-H　layer　and　water　molecules,the　ranking　of　diffusion　coefficients　of　chloride　ions　in　C-S-H　pores　in　four　solutions　is　KCl　＞　NaCl　＞　CaCl2　＞　MgCl2　©　2025　Tongji　University.　All　rights　reserved.