Phthalocyanine　(Pc)　and　its　related　derivatives　are　a　class　of　functional　materials　that　are　easily　activated　by　the　light　at　a　special　wavelength.　As　such　photosensitizer,　Pc　has　been　applied　to　photodynamic　therapy　(PDT),　in　addition　to　its　broad　applications　in　many　fields,　for　both　malignant　and　benign　diseases.　One　of　our　long-term　research　focuses　is　to　develop　Pc　for　cancer　therapy.　Herein　we　briefly　review　mechanisms　of　action　of　Pc　used　for　photodynamic　therapy,　its　pharmaceutical　development　and　molecular　modification　to　enhance　its　drugability　and　improve　its　intracellular　localization.　We　also　describe　the　current　status　of　the　Pc　derivatives　under　clinical　investigation,　and　analyze　the　methods　used　for　quantitative　analysis　of　those　Pc　derivatives.　©　2013　Elsevier　B.V.