In　order　to　reduce　the　amount　of　added　sodium　in　myofibrillar　protein　(MP)　gel,　the　effects　of　partial　substitution　of　different　chloride　salts　(CaCl2,　MgCl2,　and　KCl)　for　NaCl　on　the　gel　strength,　microstructure,　water-holding　capacity　and　rheological　properties　of　MP　gel　were　studied.　The　underlying　mechanism　of　action　of　sodium　substitutes　was　elucidated　by　using　sodium　dodecyl　sulfate-polyacrylamide　gel　electrophoresis　(SDS-PAGE)　and　intrinsic　fluorescence　spectroscopy　as　well　as　measuring　surface　hydrophobicity　and　sulfhydryl　content.　The　results　showed　that　KCl　was　the　best　substitute　for　NaCl,　followed　by　CaCl2,　and　MgCl2　was　least　effective　in　replacing　NaCl.　The　gel　strength　of　the　KCl　substitution　groups　(0.5%　KCl　+　2.5%　NaCl,　1.5%　KCl　+　1.5%　NaCl,　and　1.0%　KCl　+　2.0%　NaCl;　m/m)　was　better　than　that　of　the　control　group　(3%　NaCl),　while　no　significant　difference　in　water-holding　capacity　was　found　between　the　two　groups　(P　＞　0.05).　The　gel　strength　of　the　1.5%　CaCl2　+　1.5%　NaCl　group　decreased　significantly　(P　＜　0.05),　and　the　water-holding　capacity　decreased　first　and　then　increased.　The　gel　strength　significantly　decreased　(P　＜　0.05)　and　the　water-holding　capacity　increased　in　the　MgCl2　substitution　groups.　In　terms　of　rheological　properties,　the　storage　modulus　(G’)　of　the　KCl　substitution　groups　was　significantly　higher　than　that　of　the　control　group.　Substitution　of　CaCl2　and　MgCl2　increased　the　surface　hydrophobicity　of　MP　and　decreased　the　sulfhydryl　content.　Substitution　of　CaCl2,　MgCl2,　and　KCl　resulted　in　a　blue　shift　in　intrinsic　fluorescence　spectra.　At　low　substitution　levels　(0.5%),　the　microstructure　of　MP　gel　showed　no　significant　difference　from　that　of　the　control　group.　The　above　results　indicate　that　CaCl2,　MgCl2　and　KCl　can　be　used　to　partially　substitute　NaCl　in　surimi　gel　products.　©　2023　Chinese　Chamber　of　Commerce.　All　rights　reserved.