Sulfonate　and/or　phthalimidomethyl　phthalocyanine　zincs　are　obtained　by　the　condensation　reaction　of　anhydrous　zinc　acetate　and　two　precursors,　i.e.　4-phthalimidomethyl　phthalonitrile　and　4-(potassium　sulfonated)　phthalonitrile.　The　ZnPcS　n　P　m　mixture　was　separated　into　5　components　according　to　the　number　of　substituted　sulfonate　groups　and　each　component　which　has　the　same　chemical　constituent　consists　of　different　regioisomers.　An　HPLC　method　in　isocratic　conditions　was　developed　to　exercise　quality　control　and　make　quantitative　analysis　of　the　photosensitizer,　di-(potassium　sulfonate)-diphthalimidomethyl　phthalocyanine　zinc　(abbreviated　as　ZnPcS　2P2,　here,　S　represents　sulfonate　group,　P　the　phthalimidomethyl　group　and　ZnPc　the　phthalocyanine　zinc).　Furthermore,　by　comparing　the　retention　behavior　of　ZnPcS2P2　with　that　of　ZnPcS2,　positional　structure　of　isomers　of　ZnPcS2P2　was　speculated.　Reversed-phase　HPLC　method　with　TEA-phosphate　buffer　and　DMF　as　eluents　in　gradient　conditions　has　been　proved　to　be　a　powerful　tool　for　the　separation　of　such　complex　system.　©　2008　Science　in　China　Press　and　Springer-Verlag　GmbH.