An　unsymmetrical　diimide-disulfonato　plithalocyanatozinc　dipotassium　salt　was　first　synthesized　by　direct　condensation　of　1,2,4,5-tetracarboxylicbenzene　with　4-sulfophthalic　acid　mono-potassium　salt.　Then,　the　condensed　product　was　separated　by　reverse　HPLC　method　and　further　purified　by　a　membrane　separation　method.　The　structure　of　the　title　isomer　was　characterized　by　UV-Vis,　IR,　elemental　analysis　as　well　as　H-1　NMR.　(C)　2004　Elsevier　B.V.　All　rights　reserved.