The　effects　of　different　salts　on　the　self-assembly　of　the　carboxylate　Gemini　surfactant　O,O＇-bis　(sodium　2-dodecylcarboxylate)-p-dibenzenediol　(referred　to　as　C-12　phi　C-2(12))　were　studied　using　dynamic　light　scattering　measurements.　The　results　showed　that　the　addition　of　salts　induced　the　transition　of　the　networklike　aggregates　into　two　new　aggregates　with　small　(hydrodynamic　radii　R-h,R-app　of　several　nanometers)　and　large　(R-h,R-app＞　100　nm)　sizes,　which　coexisted　in　solution.　A　solubilization　test　using　a　1,6-diphenyl-1,3,5-hexatriene　(DPH)　probe　confirmed　that　the　small　aggregates　were　spherical　micelles　with　a　core-shell　structure.　Rheological　measurements　suggested　that　the　large　aggregates　were　threadlike　micelles.　The　aggregate　transition　was　attributed　to　the　instability　of　the　initially　formed　network-like　aggregates.　The　added　counter-　ions　associated　with　the　head-groups　of　C-12　phi　C-2(12),　which　destroyed　the　hydrophile-lipophile　balance　and　resulted　in　the　aggregate　transition.　The　salt　effect　followed　the　order:　MgCl2＞　NaCl,　Bu4NBr＞　Me4NBr＞　Et4NBr＞　Pr4NBr,　where　Bu4NBr　is　special　and　not　in　the　order　of　electrostatic　attraction　since　it　provides　an　additional　force　through　the　hydrophobic　interaction　of　its　butyls　with　the　alkyl　tails　of　C-12　phi　C-2(12).