The　aim　of　this　study　is　to　investigate　the　cooperation　effects　of　calcium　(CaSO4)　and　magnesium　(MgCl2　and　MgSO4)　salts　on　the　rheological　and　microstructural　properties,　and　water　holding　capacity　(WHC)　of　soy　protein　isolate　(SPI)　emulsion-based　tofu　gels.　Small-deformation　rheology　indicated　that　the　aggregation　power　of　the　three　coagulants　follows　the　order　of　MgCl2　＞　MgSO4　＞　CaSO4,　and　the　coagulants　containing　MgSO4　(5　and　10　mM)　and　MgCl2　(5　mM)　promote　to　produce　stronger　gels　with　greater　gel　firmness　and　rigidity.　When　compared　with　single　CaSO4　as　the　coagulant,　a　low　concentration　of　Mg2+　helped　to　form　compact　protein　aggregates　and　facilitated　gel　homogeneity　and　resistance　to　deformation.　The　WHC　of　the　gels　was　significantly　enhanced　(p　＜　0.05)　by　the　action　of　5　mM　MgSO4.　The　relationships　between　aggregates　induced　by　the　coagulants　and　gel　properties,　as　well　as　the　influencing　mechanism　were　discussed.　The　findings　provide　valuable　information　for　understanding　the　coagulant-related　gelation　mechanism　of　protein　and　the　application　of　SPI　emulsion-based　gels　with　improved　properties　in　food　industry.