To　develop　highly　efficient　photosensitizers　for　photodynamic　therapy,　herein　a　zinc(II)　phthalocyanine-folate　conjugate　(PcN-FA)　used　to　construct　an　activatable　nanophotosensitizer　(NanoPcN-FA)　through　a　facile　self　assembly.　The　self-assembled　nanophotosensitizer　(NanoPcN)　without　folate-modification　was　used　as　a　negative　control.　After　self-assembly,　the　photoactivities　of　NanoPcN-FA　was　quenched.　The　in　vitro　studies　showed　that　NanoPcN-FA　could　be　taken　in　by　folate-receptor　(FR)-positive　SKOV3　cells　and　activated　in　the　cells.　It　also　exhibited　slightly　higher　photocytotoxicity　against　SKOV3　cells　than　NanoPcN.　Moreover,　the　competitive　assay　confirmed　that　the　cellular　uptake　of　NanoPcN-FA　was　through　a　FR-mediated　process.　Finally,　the　in　vivo　results　indicated　that　NanoPcN-FA　could　target　tumor　tissue　of　S180　rat　ascitic　tumor-bearing　mice　due　to　the　folic　acid　(FA)　ligand,　leading　to　a　highly　efficient　antitumor　photodynamic　efficacy　with　the　tumor　inhibition　rate　of　95%.