Photodynamic　therapy　(PDT)　is　an　innovative　and　promising　modality　to　treat　various　tumors.　In　this　study,　two　novel　zinc(II)　phthalocyanines　substituted　with　quinolin-8-yloxy　groups　at　the　a-position,　namely　mono(quinolin-8-yloxy)　zinc(II)　phthalocyanine　(ZnPc-Q1)　and　tetra(quinolin8-　yloxy)　zinc(II)　phthalocyanine　(ZnPc-Q4),　have　been　synthesized　and　fully　characterized.　With　quinolin-8-yloxy,　these　two　phthalocyanines　exhibit　less　self-aggregation　in　DMF　and　culture　medium,　high　singlet　oxygen　quantum　yields,　mitochondria　localization　and　high　photodynamic　activities　(IC50　values　as　low　as　2　nM).　Compared　to　ZnPc-Q4,　ZnPc-Q1　exhibits　higher　cellular　uptake　and　lower　IC50　values.　Benefitting　from　its　higher　anticancer　efficacy　and　lack　of　isomers,　ZnPc-Q1　is　a　highly　promising　anticancer　agent　in　clinical　application.