Supramolecular　chemistry　provides　a　＂bottom-up＂　method　to　fabricate　nanostructures　for　biomedical　applications.　Herein,　we　report　a　facile　strategy　to　directly　assemble　a　phthalocyanine　photo-sensitizer　(PcS)　with　an　anticancer　drug　mitoxantrone　(MA)　to　form　uniform　nanostructures　(PcS　MA),　which　not　only　display　nanoscale　optical　properties　but　also　have　the　capability　of　undergoing　nucleic　acid-responsive　disassembly.　These　supramolecular　assemblies　possess　activatable　fluorescence　emission　and　singlet　oxygen　generation　associated　with　the　formation　of　free　PcS,　mild　photothermal　heating,　and　a　concomitant　chemotherapeutic　effect　associated　with　the　formation　of　free　MA.　In　vivo　evaluations　indicate　that　PcS-MA　nanostructures　have　a　high　level　of　accumulation　in　tumor　tissues,　are　capable　of　being　used　for　cancer　imaging,　and　have　significantly　improved　anticancer　effect　compared　to　that　of　PcS.　This　study　demonstrates　an　attractive　strategy　for　overcoming　the　limitations　of　photodynamic　cancer　therapy.